CN113890332A

CN113890332A - Circuit for hybrid switched capacitor converter

Info

Publication number: CN113890332A
Application number: CN202111108802.0A
Authority: CN
Inventors: 阿尔贝托·亚历山德罗·安吉洛·普杰利; 托马斯·李; 金元英; 约翰·克罗斯利; 汉-福·勒
Original assignee: Lion Semiconductor Inc
Current assignee: Lion Semiconductor Inc
Priority date: 2017-09-05
Filing date: 2018-09-05
Publication date: 2022-01-04
Also published as: CN111328388A; KR20200039803A; CN111328388B; EP3679447A1; WO2019050907A1; EP3679447A4; KR102137359B1

Abstract

Disclosed is a circuit for a hybrid switched capacitor converter, the circuit being connected to a first capacitor, a second capacitor and an inductor, comprising: an inductor with a first side connected to V_IN(ii) a A first switch having a first side connected to the second side of the inductor and a second side not connected to the second side of the inductor; a second switch having a first side connected to V_IN(ii) a A first capacitor having a first side connected to a second side of the second switch;a third switch having a first side connected to a second side of the first switch; a fourth switch having a first side connected to a second side of the third switch; a fifth switch having a first side connected to the second side of the first capacitor and the second side of the fourth switch, and having a second side coupled to the voltage source; and a second capacitor having a first side connected to the first side of the fourth switch and a second side connected to the second side of the fifth switch.

Description

Circuit for hybrid switched capacitor converter

The present application is a divisional application entitled "circuit for hybrid switched capacitor converter" with application number 201880070698.0, application date 2018, 9, and 5.

Cross Reference to Related Applications

This application claims the benefit of U.S. patent application No. 15/695,955 filed on 5.9.2017, which is incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates to apparatus, systems, and methods for providing a reconfigurable Dickson Star switched capacitor voltage regulator and/or providing a hybrid (e.g., two-stage) voltage regulator.

Background

There is a strong demand for reducing the size of electronic systems. Size reduction is particularly desirable in mobile electronic products where space is at a premium, but also in servers placed in large data centers, since it is important to crowd as many servers as possible into fixed-size space assets.

Some of the largest components in electronic systems are voltage regulators (also referred to as power regulators). Voltage regulators typically include a large number of bulky off-chip components and are used to deliver voltage to circuits such as integrated chips, including: a processor, a memory device (e.g., Dynamic Read Access Memory (DRAM)), a Radio Frequency (RF) chip, a WiFi combination chip, and a power amplifier.

To deliver power efficiently, voltage regulators may use a "buck" topology. Such regulators are called buck regulators. Buck regulators use inductors to transfer charge from a power source to an output load. The buck regulator may use power switches (each at a different point in time) to connect or disconnect the inductor to or from different voltages to provide the output voltage as a weighted average of the different voltages. The buck regulator may regulate the output voltage by controlling the amount of time the inductor is coupled to different voltages.

Unfortunately, buck regulators are not well suited for highly integrated electronic systems. The conversion efficiency of a buck regulator depends on the size of the inductor, especially when the power conversion ratio is high and when the current consumed by the output load is high. Because inductors can occupy large areas and are bulky and cannot be integrated on-chip or on-package, existing buck regulators typically use a large number of off-chip inductor components. This strategy typically requires a large area on the printed circuit board, which in turn increases the size of the electronic device. The challenges are exacerbated as mobile systems on chip (SoC) become more complex and require an increasingly large number of voltage domains to be delivered by the voltage regulator.

Therefore, new voltage regulator circuits are desired.

Disclosure of Invention

A circuit for a hybrid switched capacitor converter is provided. In some embodiments, there is provided a circuit comprising: an inductor having a first side and a second side, wherein the first side is connected to an input voltage; a first switch having a first side and a second side, wherein the first side is connected to the second side of the inductor and the second side is not connected to the second side of the inductor; a second switch having a first side and a second side, wherein the first side is connected to the input voltage; a first capacitor having a first side and a second side, wherein the first side is connected to the second side of the second switch; a third switch having a first side and a second side, wherein the first side is connected to the second side of the first switch; a fourth switch having a first side and a second side, wherein the first side is connected to the second side of the third switch; a fifth switch having a first side and a second side, wherein the first side is connected to the second side of the first capacitor and the second side of the fourth switch, and wherein the second side is coupled to the voltage source; a second capacitor having a first side and a second side, wherein the first side is connected to the first side of the fourth switch, and wherein the second side is connected to the second side of the fifth switch.

In some of these embodiments, at least one of the following is a transistor: a first switch, a second switch, a third switch, a fourth switch, and a fifth switch.

In some of these embodiments, at least one of the following is a MOSFET: a first switch, a second switch, a third switch, a fourth switch, and a fifth switch.

In some of these embodiments, at least one of the first switch, the second switch, the third switch, the fourth switch, and the fifth switch is a transistor; and at least one of the first switch, the second switch, the third switch, the fourth switch, and the fifth switch is controlled by the controller.

In some of these embodiments, when the circuit is in the first state: the first switch is closed; the second switch is open; the third switch is open; the fourth switch is closed; the fifth switch is open; and when the circuit is in the second state, the first switch is closed; the second switch is open; the third switch is closed; the fourth switch is open; and the fifth switch is closed.

In some of these embodiments, when the circuit is in the first state: the first switch is closed; the second switch is open; the third switch is open; the fourth switch is closed; the fifth switch is open; when the circuit is in the second state: the first switch is closed; the second switch is open; the third switch is closed; the fourth switch is open; the fifth switch is closed; when the circuit is in the third state: the first switch is open; the second switch is closed; the third switch is open; the fourth switch is closed; and the fifth switch is open; when the circuit is in the fourth state, the first switch is open; the second switch is open; the third switch is closed; the fourth switch is open; and the fifth switch is closed.

In some of these embodiments, the circuit further comprises: a sixth switch having a first side and a second side, wherein the first side is connected to the second side of the inductor; a seventh switch having a first side and a second side, wherein the first side is connected to the input voltage; a third capacitor having a first side and a second side, wherein the first side is connected to the second side of the seventh switch; an eighth switch having a first side and a second side, wherein the first side is connected to the second side of the sixth switch; a ninth switch having a first side and a second side, wherein the first side is connected to the second side of the eighth switch; a tenth switch having a first side and a second side, wherein the first side is connected to the second side of the third capacitor and the ninth second side, and wherein the second side is coupled to the voltage source.

In some of these embodiments, the circuit further comprises: a sixth switch having a first side and a second side, wherein the first side is connected to the second side of the inductor; a seventh switch having a first side and a second side, wherein the first side is connected to the input voltage; a third capacitor having a first side and a second side, wherein the first side is connected to the second side of the seventh switch; an eighth switch having a first side and a second side, wherein the first side is connected to the second side of the sixth switch; a ninth switch having a first side and a second side, wherein the first side is connected to the second side of the eighth switch; a tenth switch having a first side and a second side, wherein the first side is connected to the second side of the third capacitor and the ninth second side, and wherein the second side is coupled to the voltage source, wherein when the circuit is in the first state: the first switch is open; the second switch is closed; the third switch is open; the fourth switch is closed; the fifth switch is open; the sixth switch is open; the seventh switch is open; the eighth switch is closed; the ninth switch is open; and the tenth switch is closed; and when the circuit is in the second state: the first switch is open; the second switch is open; the third switch is closed; the fourth switch is open; the fifth switch is closed; the sixth switch is open; the seventh switch is closed; the eighth switch is open; the ninth switch is closed; and the tenth switch is open.

In some of these embodiments, the circuit further comprises: a sixth switch having a first side and a second side, wherein the first side is connected to the second side of the inductor; a seventh switch having a first side and a second side, wherein the first side is connected to the input voltage; a third capacitor having a first side and a second side, wherein the first side is connected to the second side of the seventh switch; an eighth switch having a first side and a second side, wherein the first side is connected to the second side of the sixth switch; a ninth switch having a first side and a second side, wherein the first side is connected to the second side of the eighth switch; a tenth switch having a first side and a second side, wherein the first side is connected to the second side of the third capacitor and the ninth second side, and wherein the second side is coupled to the voltage source, wherein when the circuit is in the first state: the first switch is open; the second switch is closed; the third switch is open; the fourth switch is closed; the fifth switch is open; the sixth switch is open; the seventh switch is open; the eighth switch is closed; the ninth switch is open; and the tenth switch is closed; when the circuit is in the second state: the first switch is open; the second switch is open; the third switch is closed; the fourth switch is open; the fifth switch is closed; the sixth switch is open; the seventh switch is closed; the eighth switch is open; the ninth switch is closed; and the tenth switch is open; when the circuit is in the third state: the first switch is closed; the second switch is open; the third switch is open; the fourth switch is closed; the fifth switch is open; the sixth switch is open; the seventh switch is open; the eighth switch is closed; the ninth switch is open; and the tenth switch is closed; when the circuit is in the fourth state: the first switch is open; the second switch is open; the third switch is open; the fourth switch is closed; the fifth switch is open; the sixth switch is closed; the seventh switch is open; the eighth switch is closed; the ninth switch is open; and the tenth switch is closed; when the circuit is in the fifth state: the first switch is open; the second switch is open; the third switch is closed; the fourth switch is open; the fifth switch is closed; the sixth switch is closed; the seventh switch is open; the eighth switch is open; the ninth switch is closed; and the tenth switch is open; and when the circuit is in the sixth state: the first switch is closed; the second switch is open; the third switch is closed; the fourth switch is open; the fifth switch is closed; the sixth switch is open; the seventh switch is open; the eighth switch is open; the ninth switch is closed; and the tenth switch is open.

Brief description of the drawings

Various objects, features and advantages of the disclosed subject matter can be more fully understood by reference to the following detailed description of the disclosed subject matter when considered in connection with the following drawings in which like reference numerals identify like elements.

Fig. 1A to 1B show examples of a buck regulator and its operation known in the prior art.

Figure 2 shows an example of a 3:1 buck Dickson Star SC regulator as known in the prior art.

Fig. 3A-3C illustrate an example of the operation of a 3:1 buck Dickson Star SC regulator as is known in the prior art.

Fig. 4 illustrates an example of a reconfigurable Dickson Star SC regulator that may be reconfigured to support multiple conversion ratios in accordance with some embodiments.

Fig. 5A-5C illustrate examples of operation of the reconfigurable regulator of fig. 4 for a 3:1 conversion ratio, according to some embodiments

Fig. 6A-6C illustrate examples of operation of the reconfigurable regulator of fig. 4 for a 2:1 conversion ratio, in accordance with some embodiments.

Fig. 7A-7C illustrate examples of operation of the reconfigurable regulator of fig. 4 for a 1:1 conversion ratio, in accordance with some embodiments.

FIG. 8 illustrates an example of a fixed slew ratio 4:1Dickson Star SC regulator according to some embodiments.

Fig. 9A-9C illustrate examples of operation of a 4:1Dickson Star SC regulator according to some embodiments.

Fig. 10 illustrates an example of a 4:1 reconfigurable Dickson Star SC regulator in accordance with some embodiments.

11A-11C illustrate examples of operation of a 4:1 reconfigurable Dickson Star SC regulator in a 4:1 conversion mode, according to some embodiments.

Fig. 12A-12C illustrate examples of operation of a 4:1 reconfigurable Dickson Star SC regulator in a 3:1 conversion mode, according to some embodiments.

Figures 13A-13C illustrate examples of operation of a 4:1 reconfigurable Dickson Star SC regulator in a 2:1 conversion mode, according to some embodiments.

Fig. 14A-14C illustrate examples of operation of a 4:1 reconfigurable Dickson Star SC regulator in a 1:1 conversion mode, according to some embodiments.

15A-15B illustrate examples of an N:1 reconfigurable Dickson Star SC regulator in accordance with some embodiments.

Fig. 16 illustrates an example of a 4:1 reconfigurable Dickson Star SC regulator in accordance with some embodiments.

17A-17C illustrate examples of operation of a 4:1 reconfigurable Dickson Star SC regulator in a 4:1 conversion mode, according to some embodiments.

Fig. 18A-18C illustrate examples of operation of a 4:1 reconfigurable Dickson Star SC regulator in a 3:1 conversion mode, according to some embodiments.

Fig. 19A-19C illustrate examples of operation of a 4:1 reconfigurable Dickson Star SC regulator in a 2:1 conversion mode, according to some embodiments.

Fig. 20A-20C illustrate examples of operation of a 4:1 reconfigurable Dickson Star SC regulator in a 1:1 conversion mode, according to some embodiments.

21A-21B illustrate examples of an N:1 reconfigurable Dickson Star SC regulator in accordance with some embodiments.

Fig. 22-24 illustrate examples of a step-up (step-up) reconfigurable Dickson Star SC regulator, according to some embodiments.

Fig. 25 illustrates an example of a two-stage voltage regulation system in which an SC regulator provides a first stage of voltage regulation, according to some embodiments.

26A-26B illustrate examples of the embodiment of FIG. 25 where the second stage regulator is a buck converter, according to some embodiments.

Fig. 27 illustrates an example of a two-stage voltage regulation system in which an SC regulator provides a second stage of voltage regulation, according to some embodiments.

28A-28B illustrate examples of a two-stage voltage regulator in which the first stage regulator consists of an inductor, according to some embodiments.

Fig. 29A-29B illustrate an example of operation of the two-stage regulator of fig. 28 in which the SC regulator is a 4:1Dickson Star Switched Capacitor (SC) regulator, according to some embodiments.

FIG. 30 illustrates duty-cycling and V for a second stage regulator according to some embodiments_TMPAn example of a voltage swing of (c).

Fig. 31 illustrates an example of a two-stage voltage regulation system in which the second stage regulator is a multi-phase voltage regulator, in accordance with some embodiments.

Fig. 32 illustrates an example of a phase relationship between the switched capacitors of fig. 31 in accordance with some embodiments.

Fig. 33 illustrates an example of a control sequence for switches that allows for maintaining a duty cycle of a first stage regulator, in accordance with some embodiments.

Fig. 34 is an example of a block diagram of a computing device including a voltage regulation system according to some embodiments.

Fig. 35A-35C show examples of operation of an N:1 buck Dickson Star SC regulator in an N:1 conversion mode, according to some embodiments.

Fig. 36A-36C illustrate examples of a hybrid converter (including an inductor and a 2:1 switched capacitor regulator) and its operation when in H21 mode, according to some embodiments.

Fig. 37A-37C illustrate examples of a hybrid converter (including an inductor and a 2:1 switched capacitor regulator) and its operation when in 2:1SC mode, according to some embodiments.

Fig. 38A-38B illustrate examples of a multiphase hybrid converter (including an inductor and a 2:1 switched capacitor regulator) and its operation when in 2:1SC mode, according to some embodiments.

Fig. 39A-39E illustrate examples of a multiphase hybrid converter (including an inductor and a 2:1 switched capacitor regulator) and its operation when in H21 mode, according to some embodiments.

Detailed Description

In the following description, numerous specific details are set forth, such as examples of apparatus, systems, and methods, as well as environments in which such apparatus, systems, and methods may operate, in order to provide a thorough understanding of the disclosed subject matter. It will be apparent, however, to one skilled in the art that the disclosed subject matter may be practiced without such specific details, and that certain features that are known in the art are not described in detail in order to avoid complicating the disclosed subject matter. Additionally, it should be understood that the examples provided below are for illustrative purposes, and that other apparatuses, systems, and methods are contemplated as being within the scope of the disclosed subject matter.

Modern electronic systems have been tightly integrated as systems on a chip (SoC), which contains multiple processors and heterogeneous components (e.g., memory controllers, hardware accelerators) within a single chip. The popularity of socs in combination with more stringent power budgets has prompted control of voltage and frequency at block-specific granularity. Block-specific voltage control may allow an electronic system to only boost the voltage of the core(s) for which higher performance is desired. Such block-specific voltage control may improve power and/or performance.

However, due to cost and size limitations of off-chip voltage regulators, conventional approaches to Dynamic Voltage and Frequency Scaling (DVFS) have been implemented at a coarse level. Furthermore, due to the slow speed of off-chip voltage regulators, conventional DVFS schemes are limited to slow voltage/frequency scaling at the microsecond time scale. A faster DVFS at nanosecond timescale can save significantly more power consumed by the SoC by closely tracking the SoC voltage for rapidly changing computational demands.

In view of these shortcomings of off-chip voltage regulators, there has been increasing interest in building Integrated Voltage Regulators (IVRs) to reduce circuit board size and achieve per-core DVFS on a nanosecond timescale. The IVR may include various voltage regulators including switching regulators and low dropout linear regulators. IVR per core DVFS, which can reduce circuit board size and can achieve nanosecond time scale, is disclosed in the following articles by the inventors of the present application, including: a document entitled "System Level Analysis of Fast, Per-Core DVFS using On-Chip Switching regulations," published by Wonyoung Kim et al in the International workshop On the IEEE High Performance Computer Architecture (HPCA) On month 2 2008; a document entitled "Design technologies for full Integrated Switched-Capacitor DC-DC Converters" published in the IEEE solid State circuits Journal (JSSC) by Hanh-Phuc Le et al, 9.2011; and a document entitled "A full-Integrated 3-Level DC/DC Converter for nanosequenced-Scale DVFS", published in IEEE solid State circuits Journal (JSSC) by Wonyoung Kim et al, month 1 2012; each of these documents is herein incorporated by reference in its entirety.

One example of a switching regulator is a buck regulator. FIGS. 1A-1B illustrate buck regulation as known in the prior artExamples of devices and their operation. As shown in fig. 1A, buck regulator 100 may include an inductor 108 and two

switches

114, 116. The buck regulator 100 may connect the inductor 108 to the first voltage source V through a set of power switches 114, 116_IN104 and a second voltage source 118. In some cases, second voltage source 118 may be a grounded voltage source. External controls may be used to turn the power switches 114, 116 on and off. In some cases, the power switches 114, 116 may be controlled such that the two switches are not turned on at the same time.

In some embodiments, the power switches 114, 116 may be formed from any suitable transistors. These transistors may be implemented using MOSFET transistors, for example. More specifically, for example, in some embodiments switch 114 may be implemented using a P-channel MOSFET transistor and switch 116 may be implemented using an N-channel MOSFET transistor.

As shown in FIG. 1B, the input V of the inductor when the power switches 114, 116 are turned on and off with a period T _×102 may be between 0 and V with a period T_INAnd swings. Inductor 108 and capacitor 120 operate as a low pass filter, which is paired with V over time _×102 are averaged so as to provide a regulator output V_OUTA signal with a small voltage ripple is created at 110. Output voltage V _OUT110 may depend on inductor 108 being coupled to first voltage source V _IN104, and the amount of time that inductor 108 is coupled to second voltage source 118 (which is 0V for purposes of illustration). For example, buck regulator 100 may convert V_OUT510 is adjusted to a level V_IND + (0V) (1-D) where D (a number between 0 and 1) is V_×Is coupled to V_INThe time portion of (c). D is also known as V _×102, of the duty cycle. The output load consuming current 106 may be any type of electronic device including a processor, memory (DRAM, NAND flash), RF chip, WiFi combo chip, power amplifier, etc.

The efficiency of buck regulator 100 can be calculated as:

wherein P is_LIndicates the power delivered to the output load, and P_OIndicating the output power of the buck regulator 108. P_LIt can be calculated as follows: p_L＝P_O-P_LOSSIn which P is_LOSSIncluding the amount of power loss during the voltage regulation process.

The primary power loss P associated with buck regulator 100_LOSSIncludes a resistive loss P caused by the parasitic resistance of inductor 108_R. When buck regulator 100 delivers power to an output load by providing current 112, buck regulator 100 ideally provides all of its output power to output load 106. However, in a practical scenario, buck regulator 100 dissipates some of its output power internally at inductor 108. Ideally, the inductor has zero resistance. Thus, the current through inductor 108 will not dissipate any power. However, in practical scenarios, the inductor is associated with a finite resistance, primarily due to the resistance of the material forming the inductor. This undesirable finite resistance of the inductor is referred to as parasitic resistance. Parasitic resistance may cause resistive power losses because parasitic resistance may cause energy to be dissipated by the current through the inductor. Thus, resistive power losses may reduce the power conversion efficiency of buck regulator 100.

When the current is alternating current, then the resistive power loss can be calculated as P_R＝I_L，RMS ²R_LWherein R is_LIs the parasitic resistance value of inductor 108, and I_L,RMSIs the root mean square of the current through inductor 108. Can be controlled by reducing the inductor current (I)_L,PP120) To reduce I_L,RMS. Therefore, buck regulator 100 may reduce inductor current I_L,PP120 peak-to-peak ripple to reduce resistive loss P_R。

There are two methods for reducing the inductor current I_L,PP120 peak-to-peak ripple. First, buck regulator 100 can be switched at high frequencyThe period T of the switching regulator is changed and decreased. However, this solution may increase the power consumed to charge and discharge the parasitic capacitance at the junction 122 between the

switches

114, 116. This capacitive power loss can be significant because the size of the

switches

114, 116 can be large (which increases parasitic capacitance) and because at V_×The voltage swing on 102 is large. This capacitive power loss can be calculated as follows: p_C＝fCV²Where C is the amount of parasitic capacitance at junction 122, f is the frequency at which buck regulator 100 switches, and V is the voltage swing at junction 122. This power loss can be significant because the size of the

switches

114, 116 is large (which increases parasitic capacitance) and because the voltage swing on V x 102 is large.

Second, buck regulator 100 may use inductor 108 with a high inductance value, thereby reducing parasitic resistance R_L. However, this approach makes the inductor 108 large, which makes integration difficult.

Another example of a switching voltage regulator is a Switched Capacitor (SC) regulator. SC regulators may use one or more capacitors (instead of inductors) to transfer charge from a power source to an output load. SC regulators may use power switches to connect/disconnect one or more capacitors from different voltages (with each different voltage connected at a different point in time) to provide an output voltage that is a weighted average of the different voltages. The SC regulator can control the output voltage by changing the configuration, sequence, and duty cycle with which the capacitors are coupled to each other. Since the capacitor is easier to integrate on a chip or on a package than the inductor, it is easier to implement an SC IVR with a small size.

One type of SC regulator is the Dickson Star SC regulator. An example of a 3:1 buck Dickson Star SC regulator (a buck Dickson Star SC regulator configured to divide an input voltage level by 1/3) is shown in fig. 2. The Dickson Star SC regulator has several advantages over other SC regulator topologies. First, it uses fewer capacitors than other SC regulator topologies, such as a stepped SC regulator. Second, it uses transistors with lower voltage ratings as switches compared to other SC regulator topologies such as series-to-parallel (SC) voltage regulators. Third, it can be more easily scaled to higher input voltages than other SC regulator topologies, such as series-parallel SC regulators.

The Dickson Star SC regulator 200 may include: switched capacitor C1 _FLY204 and C2 _FLY206; and a switch matrix including a plurality of

switches

216, 218, 220, 222, 224, 226, and 228, the plurality of

switches

216 and 228 configured to switch the capacitor C1 _FLY204 and C2 _FLY206 are electrically coupled to an input voltage node V _IN202. Output voltage node V _OUT208 and ground node GND 210. Output node V _OUT208 are coupled to an output load I_OUT212 and a decoupling capacitor C _OUT 214。

Fig. 3A-3C illustrate the basic operation of the Dickson Star SC regulator 200. As shown in fig. 3C, the Dickson Star SC regulator 200 is duty cycled with a duty cycle D over time between state0 (shown in fig. 3A) and state1 (shown in fig. 3B). The value of the duty cycle (D) may be any value between 0 and 1, and is preferably between 0.25 and 0.75.

When the capacitor C1 is switched_FLY204 and C2 _FLY206 are sufficiently large, the voltage V across these switched capacitors_C1FLY、V_C2FLYRemain substantially constant between state0 and state1, respectively. In addition, a generally large decoupling capacitor C _OUT214 are always coupled to the output V _OUT208 to reduce noise on the output. Thus, the output voltage V _OUT208 remain substantially constant in state0 and state 1. Based on these characteristics, the following voltage relationships can be derived:

state 0: v _OUT 208+V_C1FLY＝V_C2FLY

State 1: v _OUT 208＝V_C1FLY

State 1: v _OUT 208+V_C2FLY＝V _IN 202

By eliminating V from these relationships_C1FLYAnd V_C2FLYThe following relationship can be derived:

V_OUT＝(1/3)×V_IN

this indicates that the alternation between state0 and state1 provides a 3:1 buck voltage regulation. This 3:1 buck Dickson Star SC regulator design can be extended to an N:1 buck Dickson Star SC regulator, where N is a number greater than 3.

Fig. 35A-35B illustrate the topology and operation of an N:1 buck Dickson Star SC regulator. An N:1 buck Dickson Star SC regulator may include a capacitor matrix (also referred to as a capacitor bank). The capacitor matrix may include a first capacitor sub-matrix and a second capacitor sub-matrix. The capacitors in the first sub-matrix of capacitors are referred to as C (1, j), where the first index "1" refers to the "first" sub-matrix of capacitors and the second index "j" refers to the jth capacitor in the first sub-matrix of capacitors. Likewise, the capacitors in the second sub-array of capacitors are referred to as C (2, j). In fig. 35A to 35B, the first capacitor sub-matrix includes M capacitors; and the second sub-matrix of capacitors comprises K capacitors. M may be equal to floor (N/2) and K may be equal to floor ((N-1)/2).

The N:1 buck Dickson-Star SC regulator includes a plurality of switch matrices. The switches in the first switch sub-matrix comprise the bottom four switches SW 1216, SW 2218, SW 3220, SW 4222. The switches in the second sub-matrix of switches are referred to as SW (2, j), where the index "j" refers to the jth switch in the switch matrix.

In fig. 35A to 35B, the number of switches and the connections of the switches in the first switch submatrices SW 1216, SW 2218, SW 3220, SW 4222 do not change regardless of the value of "N". The second switch submatrix includes F number of switches and the value F may be equal to M + K + 1.

SW 1216 is connected between one terminal of SW 2218 and GND 210. The other terminal of SW 2218 is connected to V _OUT208, and one terminal of SW 3220. SW 4222 is connected between the other terminal of SW 3220 and GND 210. SW (2,1) is connected between one terminal of C (1,1) and V _OUT208. In a second switch sub-matrixThe remaining switches are connected between the capacitors in the first sub-matrix of capacitors and the capacitors in the second sub-matrix of capacitors. For example SW (2, j) (where j>2) is connected between one terminal of C (1, p) and one terminal of C (2, q), where p equals ceiling (j/2) and the value q equals floor (j/2). The connection between SW 1216 and SW 2218 is connected to the other terminal of C (1, p), and the connection between SW 3220 and SW 4222 is connected to the other terminal of C (2, q).

The N:1 buck Dickson-Star SC regulator may duty cycle between state0 and state1 as shown in fig. 35A and 35B, respectively, by turning on and off the switches in the switch matrix.

Fig. 35A-35B illustrate operation of an N:1 buck Dickson Star SC regulator in an N:1 switching mode. In state0, in the first switch sub-matrix, SW 1216 and SW 3220 are turned off (i.e., open), and SW 2218 and SW 4222 are turned on (i.e., closed). In the second switch sub-matrix, all odd-indexed switches are open (i.e., open) and all even-indexed switches are closed (i.e., closed). Subsequently, in state1, all switch states are inverted compared to state 0.

The advantage of this switch configuration is that, no matter how large N is, all switches have only at most V applied across them_OUT208. One disadvantage is that some capacitors have a high voltage applied across them, which requires high voltage rated capacitors, which can be bulky and expensive. In some embodiments, the voltage across the capacitor, V_C(1，p)And V_C(2，q)Is equal to ((p-1). times.2 + 1). times.V _OUT208 and qx 2 xV _OUT208. Thus, this Dickson Star configuration is useful when low voltage switches and high voltage capacitors are available.

Although a Dickson Star SC regulator may be useful, such a design would still be limited to a single slew ratio (input voltage V)_IN202 and an output voltage V_OUTThe ratio N:1 between 208 and cannot effectively regulate the voltage to provide other conversion ratios.

One disadvantage of using a single conversion ratio SC regulator is the limited range of output voltages. In general, the efficiency of an SC regulator may decrease at an output voltage that is not a predetermined fraction (e.g., 1/N) of the input voltage. SC regulators are typically optimized to achieve high efficiency at a single conversion ratio. For example, when an SC regulator is coupled to a battery that provides 3.3V, the SC regulator may be optimized to receive 3.3V and provide a fixed output voltage of 1.1V. In this case, the efficiency of the SC regulator is optimized to provide an output voltage of 1.1V — when the output voltage deviates from 1.1V, the conversion of the SC regulator will decrease. In other words, the SC regulator may be optimized to provide high efficiency at a conversion ratio of 3:1, and the efficiency of the SC regulator may decrease as the conversion ratio deviates from 3: 1. This efficiency reduction is unfortunate because a system on a chip (SoC) can operate at many voltage levels, and it would be desirable to use a single SC regulator to accommodate all those voltage levels in the SoC.

One way to support multiple conversion ratios is to provide multiple regulators each dedicated to a particular conversion ratio and enable only one of these regulators depending on which conversion ratio needs to be supported. However, this requires many redundant capacitors and switches. For example, when a 3:1 regulator is being used, all switches and capacitors of the 2:1 and 1:1 regulators remain idle and are not used. Redundant capacitors and switches require space assets on the integrated circuit chip and add cost, both of which are undesirable.

It is therefore desirable to provide a single SC regulator that can achieve high efficiency at multiple conversion ratios. Stated differently, it is desirable to provide a single SC regulator that can be reconfigured for one of many conversion ratios (e.g., 1/2, 1/3, 2/3, 2/5, 3/5, 4/5) so that the single SC regulator can efficiently accommodate one of many output voltage levels.

The present disclosure shows a reconfigurable Dickson Star SC regulator that can support multiple slew ratios by being reconfigured between various modes. Reconfigurable Dickson Star SC regulators are designed to reduce the number of redundant capacitors by reusing capacitors and switches across multiple operating modes (across multiple conversion ratios).

In some embodiments, the reconfigurable Dickson Star SC regulator includes a regular Dickson Star SC regulator and a mode switch matrix. The mode switch matrix includes a plurality of switches coupled to a regular Dickson Star SC modulator. Depending on the desired slew rate, one or more switches in the mode switch matrix may be enabled to reconfigure the arrangement of capacitors in a regular Dickson Star SC regulator. In this way, the mode switch matrix can reconfigure the slew ratio of the regular fixed slew mode Dickson Star SC modulator.

In some embodiments, depending on the reconfigured switching ratio of the reconfigurable Dickson Star SC regulator, the switches in the regular fixed switching mode Dickson Star SC regulator may be controlled differently (as compared to its regular fixed switching mode operation) to account for the reconfiguration arrangement of the capacitors.

In the foregoing discussion, an N:1 reconfigurable Dickson Star SC regulator refers to a reconfigurable Dickson Star SC regulator that can be reconfigured to provide a signal having any of M:1 conversion ratios, where M is a value between 1 and N.

Fig. 4 illustrates an example of a reconfigurable Dickson Star SC regulator that may be reconfigured to support multiple conversion ratios in accordance with some embodiments. Fig. 4 shows a 3:1 reconfigurable Dickson Star SC regulator 400 that can be reconfigured to have one of the following conversion ratios: 3:1, 2:1 and 1: 1. 3:1 reconfigurable Dickson Star SC regulator 400 includes: the fixed 3:1Dickson Star SC regulator 200 in fig. 2, identified using block 404, and a mode switch matrix 406 including a single mode switch SW 8402. This additional mode switch 402 may be selectively operated to transform the fixed 3:1Dickson Star SC regulator of fig. 2 into a 3:1 reconfigurable Dickson Star SC regulator.

Fig. 5-7 illustrate operation of the reconfigurable regulator of fig. 4 for conversion ratios 3:1, 2:1, 1:1, respectively, in accordance with some embodiments. As shown in fig. 5A-5C, to operate the reconfigurable Dickson Star SC regulator 400 in the 3:1 conversion mode, the mode switch SW 8402 may simply be turned off (in the "on" position), and the fixed 3:1Dickson Star SC regulator 404 in the reconfigurable regulator 400 may operate in the same manner as in fig. 3 (multiple switches may be duty cycled to switch the regulator between state0 and state 1).

As shown in fig. 6A-6C, to operate reconfigurable Dickson Star SC regulator 400 in a 2:1 conversion mode, switch SW 8402 may be turned on (i.e., closed) during state0 and switch SW 8402 may be turned off (i.e., open) during state when fixed 3:1 regulator 404 is duty cycled between state0 and state 1. In a sense, this 3:1 reconfigurable Dickson Star SC regulator operates in a 2:1 conversion mode because the mode switch SW 8402 switches the capacitor C1 in parallel_FLY204 and C2 _FLY206 are connected together and operate them collectively as a single large capacitor in state0, as in a conventional 2:1SC regulator. For example, in a conventional 2:1SC regulator, one switched capacitor or a plurality of switched capacitors connected in parallel acting as one switched capacitor is connected between the input and output voltages in one state and between the output voltage and ground in another state. By switching between these two states, the output voltage becomes half of the input voltage. The switches in fig. 6A-6B are turned on and off accordingly as shown in the figure so that this switched capacitor behaves as in a conventional 2:1SC regulator.

As shown in fig. 7A-7C, to operate reconfigurable Dickson Star SC regulator 400 in a 1:1 conversion mode, switch SW 8402 may be turned on (i.e., closed) during state0 and switch SW 8402 may be turned off (i.e., open) during state1 as the regulator duty cycles between state0 and state 1. The remaining switches are turned on and off accordingly so that the switched capacitor behaves as in a conventional 1:1SC regulator. For example, in a conventional 1:1SC regulator, one switched capacitor or a plurality of switched capacitors connected in parallel acting as a switched capacitor is connected between an input voltage and ground in one state and between an output voltage and ground in another state. By switching between these two states, the output voltage becomes similar to the input voltage. The switches in fig. 7A-7B are turned on and off as shown in the figure so that the switched capacitor behaves as in a conventional 1:1SC regulator.

In some embodiments, the reconfigurable Dickson Star SC regulator may be a 4:1 reconfigurable Dickson Star SC regulator. In other words, the reconfigurable Dickson Star SC regulator may be configured to provide one of the following conversion ratios 4:1, 3:1, 2:1, 1: 1. To facilitate a discussion of a 4:1 reconfigurable Dickson Star SC regulator, FIG. 8 illustrates a fixed slew ratio 4:1Dickson Star SC regulator 800. The 4:1Dickson Star SC regulator 800 has one more switched capacitor C3 as compared to the 3:1Dickson Star SC regulator 200 of FIG. 2_FLY802 and one more switch SW 9804.

Similar to the 3:1Dickson Star SC regulator 200, the 4:1 regulator 800 duty cycles between state0 and state1 to provide voltage regulation. Fig. 9A-9C illustrate duty cycles of the 4:1 regulator 800 between state0 and state 1. Assume a switched capacitor C1 _FLY 204、C2 _FLY206 and C3 _FLY802 and decoupling capacitor C _OUT214 is large, the following relationship can be derived for the two states:

state 0: v _IN 202＝V_C3FLY+V _OUT 208

State 0: v_C2FLY＝V_C1FLY+V _OUT 208

State 1: v _OUT 208＝V_C1FLY

State 1: v_C3FLY＝V _OUT 208+V_C2FLY

Wherein, V_C1FLYIs a first switched capacitor C1 _FLY204 voltage across, V_C2FLYIs a second switched capacitor C2 _FLY206 voltage across, V_C3FLYIs a third switched capacitor C3 _FLY802 across the capacitor. TheseThe relationships may be reorganized as follows:

V_C2FLY＝2×V_OUT

V_C3FLY＝3×V_OUT

V_OUT＝(1/4)×V_IN

thus, the Dickson Star SC regulator is shown in fig. 8 operating as a 4:1 buck Dickson Star SC regulator.

In some embodiments, a fixed transition mode 4:1Dickson Star SC regulator may be enhanced with a mode switch matrix to provide a 4:1 reconfigurable Dickson Star SC regulator. Fig. 10 illustrates a 4:1 reconfigurable Dickson Star SC regulator 1000 in accordance with some embodiments. The 4:1 reconfigurable Dickson Star SC regulator 1000 includes a fixed transition mode 4:1Dickson Star SC regulator and a mode switch matrix having two mode switches SW 101002 and SW 111004. The mode switch matrix is designed to reconfigure the arrangement of capacitors in a fixed transition mode 4:1Dickson Star SC regulator to be reconfigurable between 4:1, 3:1, 2:1, 1:1 transition ratios.

Figures 11A-11C illustrate operation of a 4:1 reconfigurable Dickson Star SC regulator in a 4:1 conversion mode, according to some embodiments. In this mode of operation, when the Dickson Star SC regulator is duty cycled between state0 and state1 as shown in fig. 11C, the mode switches SW 101002 and SW 111004 are also duty cycled to provide a 4:1 conversion ratio to behave similarly to SW 121 and SW 2218. For example, in state0, the first mode switch SW 101002 is open ("on") and the second mode switch SW 111004 is on ("on"); and in state1, the first mode switch SW 101002 is turned on ("closed") and the second mode switch SW 111004 is turned off ("open").

Assume a switched capacitor C1 _FLY 204、C2 _FLY206 and C3 _FLY802 and a decoupling capacitor C _OUT214 are large, the following relationship can be derived for the two states:

state 0: v _IN 202＝V_C3FLY+V _OUT 208

State 0: VC2_FLY＝V_C1FLY+V _OUT 208

State 1: v _OUT 208＝V_C1FLY

State 1: v_C3FLY＝V _OUT 208+V_C2FLY

Wherein, V_C1FLYIs a first switched capacitor C1 _FLY204 voltage across, V_C2FLYIs a second switched capacitor C2 _FLY206, and V across_C3FLYIs a third switched capacitor C3 _FLY802 across the capacitor. These relationships can be reorganized as follows:

V_C2FLY＝2×V_OUT

V_C3FLY＝3×V_OUT

V_OUT＝(1/4)×V_IN

thus, the reconfigurable Dickson Star SC regulator shown in fig. 11A-11B operates as a 4:1 buck Dickson Star SC regulator.

Figures 12A-12C illustrate operation of a 4:1 reconfigurable Dickson Star SC regulator in a 3:1 conversion mode, according to some embodiments. In this mode of operation, when the regulator is duty cycled between state0 and state1 as shown in fig. 12C, the mode switches SW 101002 and SW 111004 are also duty cycled to provide a 3:1 switching ratio. For example, in state0, the first mode switch SW 101002 is turned on ("closed") and the second mode switch SW 111004 is turned off ("open"); and in state1, the first mode switch SW 101002 is turned off ("on") and the second mode switch SW 111004 is turned on ("on").

In a sense, operation of such a 4:1 reconfigurable Dickson Star SC regulator in the 3:1 conversion mode is similar to operation of the fixed conversion mode 3:1Dickson Star SC regulator 200 of FIG. 2. For example, switched capacitor C2 _FLY206 and C3 _FLY802 are connected together in parallel to provide a larger single capacitor, which together are shown as C2 in fig. 2_FLY206. As another exampleExample, switched capacitor C1 in fig. 12A-12B _FLY204 as C1 in FIG. 2_FLY204. Thus, while the number of capacitors in the 4:1 reconfigurable Dickson Star SC regulator is different from the fixed transition mode 3:1Dickson Star SC regulator shown in fig. 2, the 4:1 reconfigurable Dickson Star SC regulator may be operated in a 3:1 transition mode by reconfiguration of the capacitor arrangement using multiple switches.

state 0: v_C2FLY＝V_C3FLY

State 0: v_C2FLY＝V_C1FLY+V _OUT 208

State 1: v _OUT 208＝V_C1FLY

State 1: v _IN 202＝V _OUT 208+V_C2FLY

V_C2FLY＝2×V _OUT 208

V_C3FLY＝2×V _OUT 208

V_OUT＝(1/3)×V_IN

thus, the reconfigurable Dickson Star SC regulator shown in fig. 12A-12C operates as a 3:1 buck Dickson Star SC regulator.

Figures 13A-13C illustrate operation of a 4:1 reconfigurable Dickson Star SC regulator in a 2:1 conversion mode, according to some embodiments. In this mode of operation, when the Dickson Star SC regulator is duty cycled between state0 and state1 as shown in fig. 13C, the mode switches SW 101002 and SW 111004 are also duty cycled to provide a 2:1 switching ratio. For example, in state0, the first mode switch SW 101002 is open ("on") and the second mode switch SW 111004 is on ("on"); and in state1, the first mode switch SW 101002 is turned on ("closed") and the second mode switch SW 111004 is turned off ("open").

In a sense, the 4:1 reconfigurable Dickson Star SC regulator operates in a 2:1 conversion mode because the regulator will have all three switched capacitors C1 _FLY 204、C2 _FLY 206、C3 _FLY802 are connected together in parallel and operate them collectively as a single large capacitor, as in a conventional 2:1SC regulator. For example, in a conventional 2:1SC regulator, one switched capacitor or a plurality of switched capacitors connected in parallel acting as one switched capacitor is connected between an input voltage and an output voltage in one state and between the output voltage and ground in another state. By switching between these two states, the output voltage becomes half of the input voltage. The switches in fig. 13A-13B are turned on and off accordingly so that the switched capacitor behaves as in a conventional 2:1SC regulator.

Assume a switched capacitor C1 _FLY 204、C2 _FLY206 and C3 _FLY802 and a decoupling capacitor C _OUT214 is large, the following relationship can be derived for both states:

state 0: v_C1FLY＝V_C2FLY＝V_C3FLY＝V_IN 202-V _OUT 208

State 1: v_C1FLY＝V_C2FLY＝V_C3FLY＝V _OUT 208

V_C1FLY＝V_OUT

V_C2FLY＝V_OUT

V_C3FLY＝V_OUT

V_OUT＝(1/2)×V_IN

thus, the reconfigurable Dickson Star SC regulator shown in fig. 13A-13C operates as a 2:1 buck Dickson Star SC regulator.

Fig. 14A-14C illustrate operation of a 4:1 reconfigurable Dickson Star SC regulator in a 1:1 conversion mode, according to some embodiments. In this mode of operation, the mode switches SW 101002 and SW 111004 are not duty cycled when the Dickson Star SC regulator is duty cycled between state0 and state1 as shown in fig. 14C. For example, in both state0 and state1, the first mode switch SW 101002 is turned on ("closed") and the second mode switch SW 111004 is turned off ("open").

In a sense, the 4:1 reconfigurable Dickson Star SC regulator operates in a 1:1 conversion mode because the regulator will have all three switched capacitors C1 _FLY 204、C2 _FLY 206、C3 _FLY802 are connected together in parallel and operate them collectively as a single large capacitor, as in a conventional 1:1SC regulator. For example, in a conventional 1:1SC regulator, one switched capacitor or a plurality of switched capacitors connected in parallel acting as one switched capacitor is connected between an input voltage and ground in one state and between an output voltage and ground in another state. By switching between these two states, the output voltage becomes similar to the input voltage. The switches in fig. 14A to 14B are turned on and off as shown in the drawing so that the switched capacitor behaves as in a conventional 1:1SC regulator.

Assume a switched capacitor C1 _FLY 204、C2 _FLY206 and C3 _FLY802 and a decoupling capacitor C _OUT214 is larger, the following relation can be derived for the two states:

state 0: v_C1FLY＝V_C2FLY＝V_C3FLY＝V _IN 202

State 1: v_C1FLY＝V_C2FLY＝V_C3FLY＝V _OUT 208

Wherein, V_C1FLYIs a first switched capacitor C1 _FLY204 voltage across, V_C2FLYIs a second switched capacitor C2 _FLY206, and V across_C3FLYIs a third switched capacitor C3 _FLY802 across the capacitor. These relationships can be reorganized and recombined as follows:

V_C1FLY＝V_OUT

V_C2FLY＝V_OUT

V_C3FLY＝V_OUT

V_OUT＝V_IN

thus, the reconfigurable Dickson Star SC regulator shown in fig. 14A-14C operates as a 1:1 buck Dickson Star SC regulator.

In some embodiments, the 3:1 reconfigurable Dickson Star SC regulator 400 shown in fig. 4 and the 4:1 reconfigurable Dickson Star SC regulator 1000 shown in fig. 10 may be extended to an N:1 reconfigurable Dickson Star SC regulator, where N may be any number greater than 1.

Fig. 15A-15B illustrate an N:1 reconfigurable Dickson Star SC regulator, according to some embodiments.

In some embodiments, the N:1 reconfigurable Dickson Star SC regulator 1500 may include a matrix of capacitors (also referred to as a capacitor bank). The capacitor matrix may include a first capacitor sub-matrix and a second capacitor sub-matrix. The capacitors in the first capacitor sub-matrix are referred to as C (1, j), wherein a first index "1" refers to the "first" capacitor matrix and a second index "j" refers to the jth capacitor in the first capacitor sub-matrix. Likewise, the capacitor in the second capacitor sub-matrix is referred to as C (2, j). In fig. 15A to 15B, the first capacitor sub-matrix includes M capacitors; and the second sub-matrix of capacitors comprises K capacitors. In some embodiments, M is equal to floor (N/2) and K is equal to floor ((N-1)/2).

In some embodiments, the N:1 reconfigurable Dickson-Star SC regulator 1500 includes a switch matrix having: the first switch submatrix, the second switch submatrix, the third switch submatrix, the fourth switch submatrix and the fifth switch submatrix.

The switches in the first switch sub-matrix are referred to as SW (1, j), wherein the first index "1" refers to the "first" switch matrix and the second index "j" refers to the jth switch in the first switch sub-matrix. Likewise, the switches in the second switch sub-matrix are referred to as SW (2, j); the switches in the third switch sub-matrix are called SW (3, j); the switches in the fourth switch sub-matrix are referred to as SW (4, j); and the switches in the fifth switch sub-matrix are referred to as SW (5, j).

In fig. 15A to 15B, the first switch submatrix and the second switch submatrix each include M switches; the third switch sub-matrix and the fourth switch sub-matrix each comprise K switches; and the fifth switch sub-matrix comprises L switches. In some embodiments, M is equal to floor (N/2); k is equal to floor ((N-1)/2); and L is equal to N.

In some embodiments, regulator 1500 can duty cycle between state0 and state1 by turning on and off switches in the switch matrix of regulator 1500.

Fig. 15A-15B illustrate operation of an N:1 reconfigurable Dickson Star SC regulator 1500 in an N:1 conversion mode, in accordance with some embodiments. In state0, all switches in the first switch sub-matrix at the bottom left are turned on, while all switches in the second switch sub-matrix are turned off. Furthermore, all switches in the third switch sub-matrix are switched off, while all switches in the fourth switch sub-matrix are switched on. In the fifth switch sub-matrix, all odd-indexed switches are turned off, and all even-indexed switches are turned on. Subsequently, in state1, all switch states are inverted compared to state 0. The capacitor topology is similar to the N:1 buck Dickson Star in FIG. 35, although there are additional switches including SW (j,1), SW (j,2), SW (j,3), SW (j,4), where j is greater than 1.

In order for the N:1 reconfigurable Dickson-Star SC regulator 1500 to operate in the (N-1):1 conversion mode, the capacitors with the highest indices in the first capacitor sub-matrix (C (1, M)) and the capacitors with the highest indices in the second capacitor sub-matrix (C (2, K)) may be connected together in parallel to operate as a single capacitor. The "single" capacitor may operate similarly to (N-1) C (1, M) in a 1 fixed switching mode Dickson-Star SC regulator-which is a Dickson-Star SC regulator: equivalent to that in the absence of C (2, K) which is connected to V by means of a switch SW (5, L)_IN202), the top switch in the fifth switch matrix, which is SW (5, L), and SW (3, K) and SW (4, K), which are two switches connected to C (2, K), an N:1 fixed transition mode Dickson-Star SC regulator.

For the N:1 reconfigurable Dickson-Star SC regulator to operate in the (N-2):1 conversion mode, connected to V by the least switches of the fifth switch sub-matrix _IN202 may be connected together in parallel to operate as a single capacitor. The three capacitors include, for example, one capacitor C (1, M) with the highest index in the first capacitor sub-matrix C (1, M), and two capacitors (C (2, K), C (2, K-1)) with the highest index in the second capacitor sub-matrix. The "single" capacitor may operate similarly to (N-2) C (2, K-1) in a 1 fixed switching mode Dickson-Star SC regulator, which is a Dickson-Star SC regulator: equivalent to an N:1 fixed transition mode Dickson-Star SC regulator without C (1, M) and C (2, K), the top two switches in the fifth switch matrix, which are SW (5, L) and SW (5, L-1), and SW (1, M), SW (2, M), SW (3, K), SW (4, K), which are switches connected to C (1, M) and C (2, K).

More generally, to operate the N:1 reconfigurable Dickson-Star SC regulator in the (N-R):1 conversion mode, the minimum switches in the fifth switch sub-matrix are connected to V _IN202 "R + 1" capacitors may be connected in parallelConnected together to operate as a single capacitor and operate the remaining switches as if operating an (N-R):1 fixed transition mode Dickson-Star SC regulator.

In some embodiments, another topology of the Dickson Star SC regulator may enable reconfiguration between transition modes. Fig. 16 illustrates a 4:1 reconfigurable Dickson Star SC regulator 1600 in accordance with some embodiments. The 4:1 reconfigurable Dickson Star SC regulator 1000 in fig. 10-14 has two additional mode switches SW 101002 and SW 111004, as compared to the fixed transition mode 4:1Dickson Star SC regulator 800 in fig. 8. Fig. 16 shows a different type of 4:1 reconfigurable Dickson Star SC regulator that uses two additional mode switches SW 121602 and SW 131604 in different positions.

17A-17C illustrate operation of a 4:1 reconfigurable Dickson Star SC regulator in a 4:1 conversion mode according to some embodiments. Although the positions of the mode switches are slightly different, the capacitor topologies in state0 and state1 are the same as the capacitor topology of the regulator 1000 in fig. 11A-11B. Therefore, the relationship between the voltages across the capacitor in state0 and state1 in fig. 17A to 17B is the same as the relationship between the voltages across the capacitor in state0 and state1 in fig. 11A to 11B. As shown in fig. 11A to 11B, assume that the switched capacitor C1 _FLY 204、C2 _FLY206 and C3 _FLY802 and decoupling capacitor C _OUT214 are large, the following relationship can be derived for the two states:

state 0: v _IN 202＝VC3_FLY+V _OUT 208

State 0: VC2_FLY＝VC1_FLY+V _OUT 208

State 1: v _OUT 208＝VC1_FLY

State 1: VC3_FLY＝V _OUT 208+VC2_FLY

Wherein, VC1_FLYIs a first switched capacitor C1 _FLY204, VC2_FLYIs a second switch capacitor C2 _FLY206, and VC3_FLYIs a third switched capacitor C3 _FLY802 across. These relationships can be reorganized as follows:

V_C2FLY＝2×V_OUT

V_C3FLY＝3×V_OUT

V_OUT＝(1/4)×V_IN

thus, the reconfigurable Dickson Star SC regulator shown in fig. 17A-17B operates as a 4:1 buck Dickson Star SC regulator.

Fig. 18A-18C illustrate operation of a 4:1 reconfigurable Dickson Star SC regulator in a 3:1 conversion mode, according to some embodiments. The principle of operation in the 3:1 conversion mode is similar to that of the 3:1SC regulator shown in fig. 2. Switched capacitor C1 _FLY204 and C3 _FLY802 are connected together in parallel to operate as a single large capacitor, similar to capacitor C1 in fig. 2_FLY204. Switched capacitor C2 in fig. 18A to 18B _FLY206 and C2 in fig. 2_FLY206 operate in a similar manner.

state 0: v_C2FLY＝V_C3FLY

State 0: v_C2FLY＝V_C1FLY+V _OUT 208

State 1: v _OUT 208＝V_C1FLY

State 1: V _IN 202＝V _OUT 208+V_C2FLY

V_C2FLY＝2×V _OUT 208

V_C3FLY＝2×V _OUT 208

V_OUT＝(1/3)×V_IN

thus, the reconfigurable Dickson Star SC regulator shown in fig. 18A-18C operates as a 3:1 buck Dickson Star SC regulator.

Figures 19A-19C illustrate operation of a 4:1 reconfigurable Dickson Star SC regulator when operating in a 2:1 mode according to some embodiments. The basic principles are similar to those of the 4:1 reconfigurable Dickson Star SC regulator shown in fig. 13A-13B. Switched capacitor C1 _FLY 204、C2 _FLY 206、 C3 _FLY802 are connected in parallel to operate as a single large capacitor, like capacitor C1 _FLY 204、C2 _FLY 206、C3 _FLY802 are connected in parallel to operate as a single large capacitor in fig. 13A-13B.

state 0: v_C1FLY＝V_C2FLY＝V_C3FLY＝V_IN 202-V _OUT 208

State 1: v_C1FLY＝V_C2FLY＝V_C3FLY＝V _OUT 208

V_C1FLY＝V_OUT

V_C2FLY＝V_OUT

V_C3FLY＝V_OUT

V_OUT＝(1/2)×V_IN

thus, the reconfigurable Dickson Star SC regulator shown in fig. 19A-19C operates as a 2:1 buck Dickson Star SC regulator.

Figures 20A-20C illustrate the operation of a 4:1 reconfigurable Dickson Star SC regulator when operating in a 1:1 mode according to some embodiments. Switched capacitor C1 _FLY 204、C2 _FLY 206、C3 _FLY802 are connected in parallel to operate as a single large capacitor, like capacitor C1 _FLY 204、C2 _FLY 206、C3 _FLY802 are connected in parallel to operate as a single large capacitor in fig. 14A-14B.

state 0: v_C1FLY＝V_C2FLY＝V_C3FLY＝V _IN 202

State 1: v_C1FLY＝V_C2FLY＝V_C3FLY＝V _OUT 208

V_C1FLY＝V_OUT

V_C2FLY＝V_OUT

V_C3FLY＝V_OUT

V_OUT＝V_IN

The regulators in fig. 10 to 14 and the regulators in fig. 16 to 20 use a mode switch matrix with switch matrices located at different positions, but the final capacitor arrangement is the same. Thus, reconfigurable regulator 1000 is functionally identical to reconfigurable regulator 1600.

In some embodiments, a 4:1 reconfigurable regulator 1600 may be generalized to provide an N:1 reconfigurable regulator, where N is greater than 1. Fig. 21A-21B illustrate an N:1 reconfigurable Dickson Star SC regulator 2100 operative in accordance with some embodiments.

The N:1 reconfigurable Dickson-Star SC regulator 2100 may also include a matrix of capacitors. The capacitor matrix may include a first capacitor sub-matrix and a second capacitor sub-matrix. The capacitors in the first capacitor sub-matrix are referred to as C (1, j), wherein the first index "1" refers to the "first" capacitor matrix and the second index "j" refers to the jth capacitor in the first capacitor sub-matrix. Likewise, the capacitor in the second capacitor sub-matrix is referred to as C (2, j). In fig. 21A to 21B, the first capacitor sub-matrix includes M capacitors; and the second sub-matrix of capacitors comprises K capacitors. In some embodiments, M is equal to floor (N/2) and K is equal to floor ((N-1)/2).

In some embodiments, the N:1 reconfigurable Dickson-Star SC regulator 2100 includes a switch matrix having a first switch sub-matrix, a second switch sub-matrix, and a third switch sub-matrix.

The switches in the first switch sub-matrix are referred to as SW (1, j), wherein the first index "1" refers to the "first" switch matrix and the second index "j" refers to the jth switch in the first switch sub-matrix. Likewise, the switches in the second switch sub-matrix are referred to as SW (2, j), and the switches in the third switch sub-matrix are referred to as SW (3, j). In fig. 21A to 21B, the first switch submatrix includes E switches; the second switch submatrix comprises D switches; and the third switch sub-matrix comprises F switches. In some embodiments, E is equal to 2 × ceiling (N/2) -1; d is equal to floor (N/2); and F is equal to N.

In some embodiments, the switches in the first sub-matrix of switches connect two capacitors in the first sub-matrix of capacitors. For example, C (1, p) and C (1, p +1) are connected by SW (1, p). Similarly, the switches in the second sub-matrix of switches connect two capacitors in the second sub-matrix of capacitors. For example, C (2, p) and C (2, p +1) are connected by SW (2, p). Switches in the third sub-matrix of switches connect capacitors in the first sub-matrix of capacitors to capacitors in the second sub-matrix of capacitors. For example, C (1, p) and C (1, p +1) are connected by SW (3,2 × p), and C (1, p +1) and C (2, p) are connected by SW (3,2 × p + 1).

In some embodiments, regulator 2100 can be duty cycled between state0 and state1 by turning on and off switches in a switch matrix of regulator 2100 as shown in fig. 21A and 21B.

Fig. 21A-21B illustrate operation of an N:1 reconfigurable Dickson Star SC regulator 2100 in an N:1 conversion mode in accordance with some embodiments. In state0, in the third switch sub-matrix, all odd-indexed switches are turned off (i.e., open) and all even-indexed switches are turned on (i.e., closed). Subsequently, in state1, all switch states in the third switch sub-matrix are inverted compared to state 0. In both state0 and state1, all switches in the first switch sub-matrix and all switches in the second switch sub-matrix side are open. Although there are additional switches including the first switch matrix and the second switch matrix, the topology of the capacitor is similar to the N:1 buck Dickson Star in fig. 35, since all those switches are open.

To operate the N:1 reconfigurable Dickson-Star SC regulator 2100 in the (N-1):1 conversion mode, the minimum switches in the third switch sub-matrix (or in other words, the switches closest to the input terminals) are connected to V_INThe capacitor of 202, which is C (2, K) in fig. 21A-21B, and the capacitor in the same matrix but with a lower bit index, which is C (2, K-1) in fig. 21A-21B, may be connected together in parallel to operate as a single capacitor. In order to keep the two capacitors connected as a "single" capacitor, SW (2, D) is always on in state0 and state 1. This "single" capacitor can work similarlyIn (N-1):1 fixed switching mode C (1, M) in Dickson-Star SC regulator-which is such a Dickson-Star SC regulator: a Dickson-Star SC regulator equivalent to the N:1 fixed switching mode with and without C (2, K), SW (3, F). Since C (2, K) is no longer independent in this mode (but works with C (2, K-1)), SW (3, F-1) is turned off in both state0 and state 1. C (1, M) acts as a top capacitor, so SW (1, E) acts as a top switch, and SW (3, F) is turned off in both state0 and state 1. In summary, SW (2, D) is always on in state0 and state1, SW (3, F-1) and SW (3, F) are always off in state0 and state1, and SW (1, E) switches are on and off in state0 and state1, respectively.

For operation of an N:1 reconfigurable Dickson-Star SC regulator in an (N-2):1 conversion mode, connected to V with minimal switching _IN202 may be connected together in parallel to operate as a single capacitor. In fig. 21A to 21B, the three capacitors are C (2, K), C (1, M), and C (2, K-1). This "single" capacitor may operate similarly to (N-2) C (2, K-1) in a 1 fixed switching mode Dickson-Star SC regulator, which is a Dickson-Star SC regulator as follows: equivalent to an N:1 fixed switching mode Dickson-Star SC regulator without C (2, K), C (1, M), SW (3, F), SW (F-1). To keep the three capacitors connected as a "single" capacitor, SW (2, D) and SW (3, E-1) are always on in

states

0 and 1. Since C (2, K) and C (1, M) are no longer independently present, SW (3, F-1) and SW (3, F-2) are turned off in both state0 and state 1. C (2, K-1) acts as a top capacitor, so SW (3, F) acts as a top switch, and SW (1, E) is turned off in both state0 and state 1. In summary, SW (2, D) and SW (1, E-1) are always on in

states

0 and 1; SW (3, F-1), SW (3, F-2), SW (1, E) are always disconnected in state0 and state 1; and the SW (3, F) switch is turned off and on in state0 and state1, respectively.

More generally, to operate an N:1 reconfigurable Dickson-Star SC regulator in an (N-R):1 conversion mode, the connection to the minimum switch in the third switch sub-matrix is made byV_INThe "R + 1" capacitors of 202 may be connected together in parallel to operate as a single capacitor and the remaining switches operated as a (N-R):1 fixed switched mode Dickson-Star SC regulator.

In some embodiments, the control module is configured to perform the following switching operations to operate the N:1 reconfigurable Dickson-Star SC regulator in an (N-R):1 conversion mode. The control module is configured to turn on the top "R" switches in the first and second matrices (e.g., the R switches closest to the input voltage terminals, or in other words, the R switches with the fewest number of switches between them and the input voltage terminals), excluding the top switch SW (1, E) in the first switch sub-matrix that is directly connected to the input voltage terminals. When the first switch in the first switch sub-matrix and the second switch in the second switch sub-matrix have the same number of switches between them and the input voltage terminal and only one of them can be included in the set of R switches, then the second switch in the second switch sub-matrix will be selected. For example, if R is equal to 3, SW (2, D), SW (1, E-1), SW (2, D-1) are selected as the "3" switch closest to the input voltage terminal. The control module is configured to keep the R-switch turned on in state0 and state1 to connect the top 3 capacitors in parallel.

Furthermore, the control module is configured to open the top "R" switches in the third switch matrix (e.g., the R switches closest to the input voltage terminals, or in other words, the R switches with the least number of switches between them and the input voltage terminals), excluding the top switch SW (3, F) in the third switch matrix connected to the input voltage terminals. For example, if R is equal to 3, then SW (3, F-1), SW (3, F-2), SW (3, F-3) are always off in State0 and State 1.

Further, when R is an odd number, the control module is configured to turn off the top switch SW (3, F) in the third switch sub-matrix and operate the top switch SW (1, E) in the first switch sub-matrix as if the top switch SW (1, E) in the first switch sub-matrix were the top switch of the third switch sub-matrix.

In some embodiments, when R is an even number, the control module is configured to turn off the top switch SW (1, E) in the first switch sub-matrix and cause the top switch SW (3, F) in the third switch sub-matrix to operate as if the top switch SW (3, F) in the third switch sub-matrix were the top switch of the first switch sub-matrix.

In some embodiments, the state of the top switch is inverted compared to the top most switch in the third switch matrix that is not always open. For example, if R is equal to 3, SW (3, F) is turned off since R is an odd number. In addition, SW (3, F-1), SW (3, F-2), SW (3, F-3) are always off. Thus, the top switch, which is SW (1, E), is in a state that is inverted as compared to SW (3, F-4), which SW (3, F-4) is the topmost switch that the third switch matrix is not always open.

In some embodiments, the reconfigurable Dickson-Star SC regulator may operate as part of a voltage regulator system. The voltage regulator system may operate in multiple interleaved phases (e.g., in a time-interleaved manner within a single cycle), and the reconfigurable Dickson-Star SC regulator may be used to provide an output voltage in one of the interleaved phases. For example, a voltage regulator system may include three reconfigurable Dickson-Star SC regulators each operating 0 degrees, 120 degrees, 240 degrees out of phase, respectively.

In some embodiments, the reconfigurable Dickson-Star SC regulator may be used for various applications including Power Management Integrated Circuits (PMICs), battery chargers, LED drivers, envelope tracking power amplifiers.

In some embodiments, a switched capacitor (e.g., C1)_FLY 204，C2 _FLY206 and C3_FLY802) May be set to be proportional to the output current of the reconfigurable Dickson-Star SC regulator. For example, the capacitance of the switched capacitor may be in the range of 0.1nF/mA and 100nF/mA, depending on the target power efficiency. In some embodiments, the reconfigurable Dickson-Star SC regulator may improve its efficiency by using larger capacitance values.

In some embodiments, the reconfigurable Dickson-Star SC regulator may operate in an inverted configuration (e.g., the input and output nodes of the reconfigurable Dickson-Star SC regulator are switched). The direction of operation of the reconfigurable Dickson-Star SC regulator may be flexibly modified to accommodate various types of input voltage sources and output loads coupled to the input and output nodes of the reconfigurable Dickson-Star SC regulator.

In some embodiments, the reconfigurable Dickson-Star SC regulator may operate in a reverse direction (reverse direction) to operate it as a boost regulator. For example, an input node of the reconfigurable Dickson-Star SC regulator may be coupled to a target load (e.g., a chip), and an output node of the reconfigurable Dickson-Star SC regulator may be coupled to an input voltage source (e.g., a battery).

Fig. 22-24 illustrate boost reconfigurable Dickson

Star SC regulators

2200, 2300, and 2400, respectively, in accordance with some embodiments. Regulator 2200 is a boost reconfigurable 1:3Dickson-Star SC regulator; regulator 2300 is a boost reconfigurable 1:4Dickson-Star SC regulator; regulator 2400 is a boost reconfigurable 1:4Dickson-Star SC regulator. The boost reconfigurable Dickson-Star SC regulators in fig. 22-24 are similar to the buck regulators in fig. 6, 10 and 16, respectively, except for V _IN202 and V _OUT208 are swapped and V _IN202 is lower than V _OUT208.

In some embodiments, the reconfigurable Dickson-Star SC regulator may operate in the reverse direction to operate it as a battery charger. For example, an input node of the reconfigurable Dickson-Star SC regulator may be coupled to a power source, such as a power line of a Universal Serial Bus (USB), while an output node of the reconfigurable Dickson-Star SC regulator may be coupled to a battery such that an output voltage and an output current of the reconfigurable Dickson-Star SC regulator are used to charge the battery.

In some embodiments, the reconfigurable Dickson-Star SC regulator may be particularly useful in charging batteries in handheld devices. Handheld devices, such as smartphones, may use lithium-Ion (Li-Ion) batteries configured to provide a voltage output approximately in the range of 2.8V to 4.3V, depending on whether the battery is charged (e.g., 4.3V when fully charged, 2.8V when fully discharged). A Universal Serial Bus (USB) may be used to charge a lithium ion battery in the handheld device. The current version of the USB power cord uses 5V (and future versions of USB may use even higher voltages), which is higher than the voltage output of lithium ion batteries. Therefore, the voltage from the USB power line should be reduced in a step-down manner before it can be used to charge the lithium-ion battery. To this end, the reconfigurable Dickson-Star SC regulator may be configured to receive a power line voltage (and current) from the USB and boost a stepped-down version of the power line voltage (and current) to the lithium-ion battery so that the lithium-ion battery may be charged based on the voltage and current from the USB.

In some embodiments, The above-described configuration of charging a battery using a USB power line may be reversed for use as USB On-The-go (otg), where a battery in a first device may deliver power to a second device over USB to charge The second device. In this scenario, the battery in the first device is configured to deliver current to the battery in the second device through the USB. While the output voltage of the battery in the first device may be lower than the USB power line voltage, the reconfigurable Dickson-Star SC regulator may operate in a boost configuration to boost the output voltage of the battery to the voltage of the USB power line in a step-up manner. In this way, the battery in the first device may charge the battery in the second device through the USB power line.

In some embodiments, an SC regulator, such as a reconfigurable Dickson-Star SC regulator, may operate in conjunction with another voltage regulator to provide two-stage voltage regulation. Fig. 25 illustrates a two-stage voltage regulation system in which an SC regulator provides a first stage of voltage regulation, according to some embodiments. Fig. 25 includes a regulator 2502 and a second stage voltage regulator 2504. SC regulator 2502 may be any type of SC regulator, including, for example, one of the reconfigurable Dickson-Star SC regulators disclosed herein. In some embodiments, the second stage voltage regulator 2504 may include one or more of the following: buck regulators, SC regulators, linear regulators, and/or any type of voltage regulator capable of providing voltage regulation.

In some embodiments, SC regulator 2502 may be operated to provide an output voltage at which SC regulator 2502 may provide high efficiency and then regulate the output voltage of SC regulator 2502 using second stage regulator 2504.

For example, reconfigurable Dickson-Star SC regulator 2502 may convert input voltage 202 to V _TMP2506，V _TMP2506 is a portion of the input voltage 202 at which a reconfigurable Dickson-Star SC regulator 2502 that can provide high efficiency is located. For example, V_TMP2506 may be V_INand/N, wherein N is the step-down ratio. Second stage voltage regulator 2504 may then receive V _TMP2506 and adjusting it to provide V _OUT 208。

Fig. 26A shows the embodiment of fig. 25 where the second stage regulator is a buck converter 100, in accordance with some embodiments. Here, V _TMP2506 are adjusted by the buck converter 100 in fine steps using the plurality of power switches 114, 116 and the one or more inductors 108. Fig. 26B shows a timing chart of signals in the regulator.

The two-stage regulator (also referred to as a hybrid regulator) shown in fig. 25 to 26 relies on the fact that: SC regulators are good at dividing across a predetermined fractional value, and second regulators (such as buck regulators) may be good at regulating in fine steps across a wide range of output voltages. For example, in a 12V-to-1V buck regulator, reconfigurable Dickson-Star SC regulator 2502 may be at V _IN202 receives 12V and provides 1/6 reduced pressure, thereby reducing the pressure at V_TMP2V is provided at 2506. Then, buck regulator 100 may provide a subsequent regulation to regulate 2V to 1V. Since this two-stage regulator will step down the internal node V of the regulator 100_xThe voltage swing at is reduced to V_TMP2506 (which may be substantially less than V)_IN202) This topology may therefore reduce parasitic capacitance due to junction 122Resulting in capacitive power losses in buck regulator 100.

Fig. 27 illustrates a two-stage voltage regulation system in which an SC regulator provides a second stage of voltage regulation, according to some embodiments. Fig. 27 includes a first stage voltage regulator 2702 and an SC regulator 2704. The SC regulator 2704 may be any type of SC regulator including, for example, one of the reconfigurable Dickson-Star SC regulators disclosed herein. In some embodiments, the first stage voltage regulator 2702 may include one or more of the following: buck regulators, SC regulators, linear regulators, and/or any type of voltage regulator capable of providing voltage regulation.

In fig. 27, the first stage regulator 2702 receives an input voltage V _IN202 and takes it as output V _TMP2706 are provided to SC regulator 2704. SC regulator 2704 may subsequently adjust V _TMP2706 are stepped down to the desired output voltage 208.

When the first stage regulator 2702 is a switched inductor regulator, the two-stage voltage regulation system of fig. 27 can reduce the inductor resistive loss of the switched inductor regulator by operating the switched inductor regulator at a high switching frequency and by flowing a small amount of current through the inductor. This approach can reduce the resistive losses of the switched-inductor regulator even with small inductors having low inductance. In addition, this topology may also reduce the capacitive loss (CV) of the switched inductor regulator by limiting the voltage swing across the switch²f loss).

In some embodiments, the first stage regulator 2702 may include only an inductor. Fig. 28A illustrates a two-stage voltage regulator in which the first stage regulator consists of an inductor, according to some embodiments. FIG. 28B illustrates a timing diagram of signals in the two-stage voltage regulator of FIG. 28A, according to some embodiments. Here, the first stage regulator is a single inductor 2802. One terminal of inductor 2802 is coupled to input voltage V _IN202 and the other terminal of inductor 2802 is coupled to the input of SC regulator 2704. The input voltage of the SC regulator 2704 is referred to as V _TMP 2706。

In some embodiments, input voltage V of SC regulator 2704_TMP2706 are connected to a switched capacitor C in the SC regulator 2704_FLY2804. When the SC regulator 2704 switches between state0 and state1 (see, e.g., fig. 3A-3B), the switched capacitor C _FLY2804 Voltage potential V on the Top plate _TMP2706 are switched between two voltages V1 and V2. Based on this operation, the following relation can be derived:

V

_IN 202＝V₁D+V₂(1-D)

V₁and V₂Is passed through SC regulator 2704 and V _OUT208 is set. Therefore, V can be finely controlled based on the duty ratio D and the conversion ratio of the SC regulator 2704_IN202 and V _OUT208. An advantage of the two-stage regulator in fig. 28 is that the single stage SC regulator 2704, which may provide only an integer ratio conversion mode, can be converted to a two-stage regulator capable of providing a non-integer ratio conversion mode by the addition of only a single inductor 2802.

In some embodiments, a two-stage regulator may have a bypass switch SWI 2806 configured to short out an inductor 2802 in a first stage regulator. The bypass switch SWI 2806 allows the first stage regulator to be turned off without requiring its operation.

Fig. 29A-29B illustrate operation of the two-stage regulator of fig. 28 in which the SC regulator is a 4:1Dickson Star Switched Capacitor (SC) regulator 800 (similar to regulator 800 of fig. 8) according to some embodiments.

In some embodiments, the second stage 4:1 regulator 800 duty cycles between state0 and state1 to provide voltage regulation, as also shown in fig. 9A-9B. Assume a switched capacitor C1 _FLY 204、 C2 _FLY206 and C3 _FLY802 and a decoupling capacitor C _OUT214 are large, the following relationship can be derived for the two states:

state 0: V _TMP 2706＝V_C3FLY+V _OUT 208

State 0: V_C2FLY＝V_C1FLY+V _OUT 208

State 1: V _OUT 208＝V_C1FLY

State 1: V_C3FLY＝V _OUT 208+V_C2FLY

V_C2FLY＝2×V_OUT

V_C3FLY＝3×V_OUT

V_OUT＝(1/4)×V_TMP

thus, the second stage SC regulator operates as a 4:1 buck regulator, and V _TMP2706 at 3 XV in State0 and State1_OUTAnd 4 XV_OUTAnd swings. Duty cycle of the second stage regulator and V_TMPThe voltage swing of 2706 is shown in fig. 30.

Due to V _TMP2706 at 3 XV_OUTAnd 4 XV_OUTAnd thus the voltage swing, is regulated by inductor 2802 to provide the following relationship:

V

_IN 202＝(3×V_OUT)D+(4×V_OUT)(1-D)＝(4-D)×V_OUT

wherein D is a value between 0 and 1, and preferably between 0.25 and 0.75. In other words, the two-stage regulator in fig. 29 allows the following voltage relationships:

V_OUT＝(1/(4-D))V_IN

thus, the voltage regulator control system may control the duty cycle D between 0 and 1 to fine tune V beyond the integer conversion ratio _IN202 and V _OUT208. In a sense, the first and second stage regulators in fig. 28 have the same duty cycle D.

Fig. 31 illustrates a two-stage voltage regulation system in which the second stage regulator is a multi-phase voltage regulator, according to some embodiments. A multi-phase voltage regulator in the second stage regulator allows the first stage regulator and the second stage regulator to use independent duty cycles. This may be beneficial in some cases because the efficiency of the SC regulator may decrease when the duty cycle of the SC regulator deviates from 0.5. By allowing the first stage regulator and the second stage regulator to have independent duty cycles, the second stage regulator can operate at a high level of efficiency (e.g., a duty cycle near 0.5) regardless of the desired output voltage of the voltage regulation system.

As shown in fig. 31, in some embodiments, the second stage SC regulator has two 4:1SC regulator modules SC _ ph 03102 and SC _ ph 13104, where SC _ ph 03102 and SC _ ph 13104 operate with their own phase. In some embodiments, the two SC regulator modules are 180 degrees out of phase. According to some embodiments, the phase relationship between SC _ ph 03102 and SC _ ph 13104 is shown in fig. 32. In fig. 32, two 4:1SC regulator modules are operated at a duty cycle of 0.5, thereby achieving high efficiency.

Although the two 4:1SC regulator modules operate at a duty cycle of 0.5, the duty cycle of the switched-inductor regulator in the first stage regulator can be independently controlled. In particular, regardless of the duty cycle of the two 4:1SC regulator modules, the switched-inductor regulator may have its own duty cycle D by switching switches SW 9804 and SW 173126 out of phase with duty cycle D.

For example, C3 when both modules SC _ ph 03102 and SC _ ph 13104 are operating at a duty cycle of 0.5_FLY802 and C6 _FLY3110 voltages V13130 and V23132 on the top plate are at 3V with a duty cycle of 0.5_OUT208 and 4 XV _OUT208 as shown in the waveform of fig. 32. Due to C3 _FLY802 and C6 _FLY3110 the voltages V13130 and V23132 at the top plate are 3V at any given

time

_OUT208 and 4 XV _OUT208, and thus switches SW 9804 and SW 173126 may be turned on and off (out of phase) at duty cycle D, thereby turning V on at duty cycle D _TMP2706 are connected to3×

V

_OUT208 or 4 XV _OUT208 as shown in fig. 32. This allows the first stage regulator to operate at duty cycle D, while the second stage regulator (comprising two 4:1SC regulator modules SC _ ph 03102 and SC _ ph 13104) operates at a duty cycle of 0.5, thereby improving the operating efficiency of the second stage regulator.

When switches SW 9804 and SW 173126 are duty cycled with duty cycle D, the amount of time a particular SC module is used may depend on duty cycle D. For example, in fig. 32, the duty ratio D is less than 0.5. Thus, the first SC module 3102 is used less than 50% of the time, while the second SC module 3104 is used more than 50% of the time. In an extreme case, one SC module may be used for 100% of the time while the other SC module is used for 0% of the time. To accommodate this extreme, the size of all switches and capacitors in the two

SC modules

3102, 3104 may need to be large enough so that a single SC module can deliver the maximum required output power as if the other SC module were not present.

In some embodiments, the switches SW 9804 and SW 173126 may be controlled such that each switch SW 9804 and SW 173126 is turned on for the same amount of time while maintaining the duty cycle of the first stage regulator. In this way, the SC module in a multiphase regulator (second stage regulator) is used for the same amount of time regardless of the duty cycle of the first stage regulator. This allows the size of the switches and capacitors in the SC module to be approximately half compared to the case where a single SC module needs to be able to deliver the maximum required power.

Fig. 33 illustrates a control sequence of switches that allows each switch SW 9804 and SW 173126 to be turned on for the same amount of time while maintaining the duty cycle of the first stage regulator, according to some embodiments. In a given period of time, the first switch SW 9804 is on for 50% of the time while keeping the second switch SW 173126 off, and the second switch SW 173126 is on for 50% of the time while keeping the first switch SW 9804 off. However, the time instance at which this period starts is determined such that the voltage V is_TMP2706 at duty cycle D of 3V_OUTAnd 4 XV_OUTAnd swings.

For example, when SW 9804 is turned on and SW17 is turned off, voltage V _TMP2706 are coupled to V13130 and when SW 9804 is turned off and SW17 is turned on, the voltage V _TMP2706 are coupled to V23132. Thus, by shifting time instance 3302, it is possible to control during which V is controlled_TMP2706 at 4 XV_OUTDuty cycle D of (D). For example, when time instance 3302 is shifted to the right, duty cycle D will increase proportionally; when time instance 3302 is shifted to the left, duty cycle D is proportionally reduced. An additional benefit of this configuration is: v_TMP2706 switch at twice the frequency of the switched inductor regulator and the switched capacitor regulator. This feature may enable the use of a smaller inductor 3302 without incurring additional switching losses.

While a reconfigurable Dickson Star regulator is used to illustrate the second stage regulator, other types of SC regulators may be used for the second stage regulators in fig. 27-29 and 31. For example, the second stage regulator may include a step SC regulator, a reconfigurable step SC regulator, a series-to-parallel SC regulator, a reconfigurable series-to-parallel SC regulator, and/or any other type of SC regulator.

In some embodiments, the two-stage regulator may be used for various applications including Power Management Integrated Circuits (PMICs), battery chargers, LED drivers, envelope tracking power amplifiers.

In some embodiments, the capacitance of the switched capacitor regulator may be set to be proportional to the output current of the two-stage regulator. For example, the capacitance of the switched capacitor regulator may be in the range of 0.1nF/mA and 100nF/mA, depending on the target power efficiency. A two-stage regulator can improve its efficiency by using larger capacitance values.

In some embodiments, the two-stage regulator may operate in the reverse direction to operate it as a boost regulator. For example, an input node of the two-stage regulator may be coupled to a target load (e.g., a chip), and an output node of the two-stage regulator may be coupled to an input voltage source (e.g., a battery).

In some embodiments, the two-stage regulator may operate in the reverse direction to operate it as a battery charger. For example, an input node of the two-stage regulator may be coupled to a power source (e.g., a power line of a Universal Serial Bus (USB)), and an output node of the two-stage regulator may be coupled to a battery.

The disclosed embodiments of the two-stage regulator may be used as a battery charger in a battery operated device. For example, the output node of the two-stage regulator may be coupled to a battery such that the output voltage and output current of the two-stage regulator are used to charge the battery.

Two-stage regulators may be particularly useful in charging batteries in handheld devices. Handheld devices, such as smartphones, may use lithium-Ion (Li-Ion) batteries configured to provide a voltage output approximately in the range of 2.8V to 4.3V depending on whether the battery is charged (e.g., 4.3V when fully charged, 2.8V when fully discharged). A Universal Serial Bus (USB) may be used to charge a lithium ion battery in the handheld device. The current version of the USB power cord uses 5V (and future versions of USB may use even higher voltages), which is higher than the voltage output of lithium ion batteries. Therefore, the voltage from the USB power line should be reduced in a step-down manner before it is used to charge the lithium-ion battery. To this end, the two-stage regulator may be configured to receive the power line voltage and current from the USB and provide a stepped-down version of the power line voltage and current to the lithium-ion battery, such that the lithium-ion battery may be charged based on the voltage and current from the USB.

In some embodiments, The above-described configuration in which a battery is charged using a USB power line may be reversed for use as USB On-The-go (otg), where a battery in a first device may deliver power to a second device over USB to charge The second device. In this scenario, the battery in the first device is configured to deliver current to the battery in the second device through the USB. Although the output voltage of the battery in the first device may be lower than the power line voltage of the USB, the two-stage regulator may operate in a boost configuration to boost the output voltage of the battery to the voltage of the USB power line in a step-up manner. In this way, the battery in the first device may charge the battery in the second device through the USB power line.

FIG. 34 is a block diagram of a computing device including a voltage regulation system according to some embodiments. The computing device 3400 includes: a processor 3402, a memory 3404, one or more interfaces 3406, an accelerator 3408, and a voltage regulator system 3410. The computing device 3400 may include: additional modules, fewer modules, or any other suitable combination of modules that perform any suitable operation or combination of operations.

In some embodiments, accelerator 3408 may be implemented in hardware using an Application Specific Integrated Circuit (ASIC). The accelerator 3408 may be part of a system on a chip (SOC). In other embodiments, accelerator 3408 may be implemented in hardware using logic circuits, Programmable Logic Arrays (PLAs), Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGAs), or any other integrated circuit. In some cases, accelerator 3408 may be packaged in the same package as other integrated circuits.

In some embodiments, the voltage regulator system 3410 may be configured to provide a supply voltage to one or more of: a processor 3402, memory 3404, and/or accelerators 3408. The voltage regulator system 3410 may include one or more Voltage Regulator (VR) modules 3412-1 … 3412-N. In some embodiments, one or more of VR modules 3412-1 … 3412-N may be, for example, reconfigurable Dickson-Star SC regulators, as disclosed in fig. 4, 10, 16. In some embodiments, one or more of the VR modules 3412-1 … 3412-N may be, for example, two-stage regulators, as disclosed in fig. 27-29, 31. One or more VR modules 3412-1 … 3412-N may operate with multiple interleaved phases.

In some embodiments, the voltage regulator system 3410 may include a switch control module configured to control a configuration of switches in one or more VR modules 3412-1 … 3412-N. For example, when the switch control module receives an instruction to operate a 3:1 reconfigurable Dickson Star SC regulator in the 3:1 conversion mode (as shown in fig. 5A-5C), the switch control module may be configured to control

switches

216, 218, 220, 222, 224, 226, and 228 and mode switch SW 8402 to operate the reconfigurable Dickson Star SC regulator in the 3:1 conversion mode. As another example, when the switch control module receives an instruction to operate a 3:1 reconfigurable Dickson Star SC regulator in a 2:1 conversion mode (as shown in fig. 6A-6C), the switch control module may be configured to control

switches

216, 218, 220, 222, 224, 226, and 228 and mode switch SW 8402 to operate the reconfigurable Dickson Star SC regulator in a 2:1 conversion mode. In some embodiments, the switch control module may be synthesized using a hardware programming language. The hardware programming language may include Verilog, VHDL, Bluespec, or any other suitable hardware programming language. In other embodiments, the switch control module may be designed manually and may be disposed manually on the chip.

Computing device 3400 may communicate with other computing devices (not shown) via interface 3406. The interface 3406 may be implemented in hardware to send and receive signals in various media (such as optical, copper, and wireless) and in many different protocols, some of which may be non-transitory.

In some embodiments, the computing device 3400 may comprise a user device. The user equipment may communicate with one or more radio access networks and with a wired communication network. The user equipment may be a cellular telephone having telephone communication functionality. The user equipment may also be a smart phone providing services such as: word processing, web browsing, games, electronic book functions, operating systems, and full keyboards. The user device may also be a tablet computer that provides network access and most of the services provided by the smartphone. The user device operates using an operating system such as Symbian OS, iPhone OS, RIM's Blackberry, Windows Mobile, Linux, HP WebOS, Tizen, Android, or any other suitable operating system. The screen may be a touch screen used to input data to the mobile device, in which case the screen may be used instead of a full keyboard. The user device may also save global positioning coordinates, profile information, or other location information. The user device may also be wearable electronics.

Computing device 3400 may also include any platform capable of computing and communicating. Non-limiting examples include: a Television (TV), a video projector, a set-top box or set-top unit, a Digital Video Recorder (DVR), a computer, a netbook, a notebook, and any other audio/video device with computing capabilities. The computing device 3400 may be configured with one or more processors that process instructions and execute software that may be stored in memory. The processor also communicates with the memory and interfaces to communicate with other devices. The processor may be any applicable processor, such as a system on a chip incorporating a CPU, an application processor, and flash memory. The computing device 3400 may also provide various user interfaces such as a keyboard, touch screen, trackball, touchpad, and/or mouse. In some embodiments, computing device 3400 may also include speakers and a display device. The computing device 3400 may also include biomedical electronics.

Turning to fig. 36A-36C, a hybrid converter 3600 incorporating a 2:1SC regulator and an inductor is shown, according to some embodiments. As shown in fig. 36A, the converter 3600 may include: an inductor 3602,

capacitors

3604 and 3606, and switches 3608, 3610, 3612, 3614 and 3616. As also shown in fig. 36, a load 3618, shown as a current, may be coupled to the output of the converter 3600.

In some embodiments, inductor 3602 may be any suitable inductor formed using any suitable technique and having any suitable dimensions. For example, in some embodiments, inductor 3602 may be a discrete inductor, which in some embodiments is formed from wire having dimensions of 2 x 1.2 mm.

Capacitors

3604 and 3606 may be any suitable capacitors formed using one or more suitable techniques and, in some embodiments, have any suitable dimensions. For example, in some embodiments, these capacitors (as well as all other capacitors described herein) may be on-chip capacitors, such as: a metal-to-metal (MoM) capacitor, a metal-insulator-metal (MiM) capacitor, a MOSFET capacitor (a capacitor using a gate oxide capacitance of a MOSFET), a discrete capacitor implemented on a chip or circuit board, such as a multilayer ceramic capacitor (MLCC), a tantalum capacitor, an aluminum electrolytic capacitor, or a thin film capacitor, or any other suitable capacitor. As another example, in some embodiments,

capacitors

3604 and 3606 may have dimensions of 2 × 1.2mm and 1.6 × 1mm, respectively.

In some embodiments,

switches

3608, 3610, 3612, 3614, and 3616 may be any suitable switches formed using any suitable technique. For example, in some embodiments, the switch may be formed by a transistor, such as a MOSFET transistor. More particularly, for example, in some embodiments, some of the switches may be implemented using P-channel MOSFET transistors, while others of the switches may be implemented using N-channel MOSFET transistors. In some embodiments, the transistors may be sized to maximize efficiency. For example, larger transistors increase switching losses, while smaller transistors increase conduction losses. Thus, in some embodiments, the dimensions may be selected to maximize the efficiency for a given particular application.

The load 3618 may be any suitable load. For example, in some embodiments, the load 3618 may be a battery for a mobile device.

The converter 3600 has two "modes" of operation: a 2:1 Switched Capacitor (SC) mode using 2:1SC component 3620; and a hybrid 2:1(H21) mode, which uses inductor 3602 and switch 3610 in conjunction with a 2:1SC component. The converter may regulate the input voltage (V) being provided using a controller and connection to an adapter (or other power source) (not shown)_IN) To achieve a 2:1SC mode (in which the input voltage (V) of the converter is_IN) And an output voltage (V)_OUT) Maintaining a 2:1 ratio) ultra-high efficiency. However, there are conventional wall adapters (and other power sources) that cannot continuously adjust their output voltage to maintain a 2:1 ratio. For example, many wall adapters have a fixed 5V output. Since the output of the converter 3600 can be straightenedIs connected to a battery which may have a voltage of 3V to 4.5V, so the input-to-output voltage ratio of the converter is connected to 5V V at it_INAnd may be 5:3 (or about 1.66:1) to 5:4.5 (or about 1.11:1), rather than the desired 2: 1. To account for the mismatch, the converter may operate in H21 mode, which may support any ratio between 1:1 and 2:1 in some embodiments.

Using the 2:1SC mode and the H21 mode, the hybrid converter can be connected to V_INCan continuously adjust its output voltage to maintain a V of about 2:1_INAnd V_OUTRatio while maintaining high efficiency in 2:1SC mode (similar to a stand-alone 2:1SC charger), and can achieve V of about 2:1 when compared to when it is not possible to maintain V by entering H21 mode_INAnd V_OUTThe step-down charger at ratio is more efficient. The hybrid converter also reduces the size and cost of the solution by reusing multiple switches in the 2:1SC mode and H21 mode, as compared to using a 2:1SC charger and a separate buck charger in parallel.

Fig. 36A and 36B show hybrid converter 3600 in H21 mode and in state0 and in state1, respectively. FIG. 36C shows V _x102, as the converter changes between state0 and state 1. By adjusting the duty cycle (how much time is spent in state0 versus state 1), the hybrid converter can adjust the ratio of input voltage to output voltage. The duty cycle (D) of the regulator is set according to the required input and output voltages by the following equation:

D＝T0/(T0+T1)

(V _x102 average value) ═ V_IN(this is because the average voltage V across the two nodes across the inductor_INAnd V_xEquality required at steady state)

(V _x102 average value) ═ 2 × V_OUT*D+V_OUT(1-D) (based on FIG. 36B)

→2*V_OUT*D+V_OUT*(1-D)＝V_IN

→V_OUT*D+V_OUT＝V_IN

→V_OUT(1+D)＝V_IN

→D＝V_IN/V_OUT-1

Fig. 37A-37C show the hybrid converter 3600 in 2:1SC mode and in state0 (fig. 37A) and state1 (fig. 37B). As shown in these figures, no inductor is used because switch 3610 is open in both state0 and state1 when in 2:1SC mode.

When the hybrid converter 3600 is operating in the H21 mode (as shown in fig. 36A-36C), the duty cycles of the SC component of the hybrid regulator and the inductor component of the regulator need to be equal. The problem with this arrangement is: the SC component may be most efficient at a duty cycle of, for example, 50%, but it may be forced to operate at a duty cycle of, for example, 10% due to the required ratio of input voltage to output voltage.

To overcome this problem, in some embodiments, the duty cycle of the SC component and the inductor may be independently made using a two-phase hybrid converter 3800 as shown in fig. 38A-38B and fig. 39A-39E. For example, in some embodiments, the inductor duty cycle may be set according to the required input and output voltage values (following the equation above), while the duty cycle of the SC component may be set to achieve maximum efficiency (which is typically a 50% duty cycle).

Similar components of the converter 3800 in fig. 38A-38B and 39A-39E may be the same as the similar components described above in connection with fig. 36A-36B in some embodiments.

Fig. 38A-38B illustrate the two-phase hybrid converter 3800 when configured to operate in 2:1SC mode. As shown, no inductor is used in this mode because

switches

310 and 320 are open at the following positions: state0, SC _ ph 0; state0, SC _ ph 1; state1, SC _ ph 0; and state1, SC _ ph 1. Thus, in this mode, the converter 3800 operates as a two-phase 2:1SC regulator. That is, these switches are opened and closed in the four states and phase combinations shown in fig. 38A to 38B. In some embodiments, the states may have any suitable duty cycle, such as 50%. In some embodiments, the switches in the 1-phase portion of converter 3800 may switch at any suitable point relative to the switches in the 0-phase portion of converter 3800. For example, in some embodiments, the switches in the 1-phase portion of converter 3800 may be switched 180 degrees out of phase with the switches in the 0-phase portion of converter 3800.

Fig. 39A to 39E show the hybrid converter 3800 when configured to operate in the H21 mode. In fig. 39A to 39D, the switches SW 1310 and SW 6320 are inductor switches, and the switches SW 2312, SW 3314, SW 4316, SW 5318, SW 7322, SW 8324, SW 9326, and SW 10328 are SC switches. During operation of converter 3800 in H21 mode, both the inductor switch and the SC switch have two different states and they iterate between these two states. The two states of the inductor switch are referred to herein as L _ state0 and L _ state1, and the two states of the SC switch are referred to herein as SC _ state0 and SC _ state 1. For example, the following may be the switching configuration for each of these four states:

l _ state 0: SW1 on and SW6 off

L _ state 1: SW1 is OFF and SW6 is ON

SC _ state 0: (SW4, SW8, SW10) is on, and (SW3, SW5, SW9) is off

SC _ state 1: (SW4, SW8, SW10) is OFF, (SW3, SW5, SW9) is ON and SW2 and SW7 are always OFF. The time spent in L _ state0 versus L _ state1 determines the duty cycle of the inductor. The time spent in SC _ state0 versus SC _ state1 determines the duty cycle of the SC. In some embodiments, the inductor switch may iterate between L _ state0 and L _ state1 at one duty cycle, and the SC switch may iterate between SC _ state0 and SC _ state1 at a different duty cycle.

Fig. 39E illustrates a timing diagram according to a hybrid switch 3800 that can iterate between states 0-3 in some embodiments. The operation of each of these states is as follows:

state 0: l _ state0, SC _ state0

State 1: l _ state1, SC _ state0

State 2: l _ state1, SC _ state1

State 3: l _ state0, SC _ state1

In this particular example as shown in fig. 39E, the duty cycle of the SC component is fixed at 50%, but it may be any suitable value and the duty cycle of the inductor switch is D. The inductor switch can adjust D independently of the duty cycle of the SC component by adjusting the time spent in each state0 to 3. If the efficiency of the SC section is maximized at a 50% duty cycle, the SC duty cycle may be fixed at 50% while the inductor duty cycle D may be adjusted to support various input to output voltage ratios.

In some cases, certain switches may be removed to reduce the area allocated for transistors in the swap limited mode of operation. For example, if the converter is good only when operating under H21 and disabling 2:1SC mode, switch 3608 in fig. 36A and SW 2312 and SW 7322 in fig. 39A-39D may be removed.

The switches in fig. 36A, 36B, 37A, 37B, 38A, 38B, and 39A-39D may be controlled by any suitable controller. For example, when the switches are implemented as MOSFETs, the switches may be controlled by a controller applying an appropriate voltage to the gate of the MOSFET to provide an open or closed connection between the source and drain of the MOSFET. The controller may be any suitable device or circuit. For example, the controller may be a hardware processor that executes software loaded into the hardware processor from memory. As another example, the controller may be a dedicated logic circuit, a field programmable gate array, and/or any other suitable device or circuit for providing suitable control signals.

It is to be understood that the disclosed subject matter is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosed subject matter is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conception, upon which disclosure is based, may be utilized as a basis for the designing of other structures, devices, systems and methods for carrying out the several purposes of the disclosed subject matter. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the disclosed subject matter.

While the disclosed subject matter has been described and illustrated in the foregoing exemplary embodiments, it should be understood that the present disclosure has been made only by way of example, and that numerous changes in the details of the embodiments of the disclosed subject matter may be made without departing from the spirit and scope of the disclosed subject matter, which is limited only by the following claims.

Claims

1. A circuit for connection to a first capacitor, a second capacitor and an inductor, the inductor having a first side connected to an input voltage, the circuit comprising:

a first switch having a first side and a second side, wherein the first side thereof is connected to the second side of the inductor;

a second switch having a first side and a second side, wherein the first side is connected to the input voltage and the second side is connected to the first side of the first capacitor;

a third switch having a first side and a second side, wherein the first side thereof is connected to the second side of the first switch;

a fourth switch having a first side and a second side, wherein the first side thereof is connected to the second side of the third switch and the first side of the second capacitor; and

a fifth switch having a first side and a second side, wherein the first side thereof is connected to the second side of the first capacitor and the second side of the fourth switch, and wherein the second side thereof is coupled to a voltage source and the second side of the second capacitor.

2. The circuit of claim 1, wherein at least one of the first switch, the second switch, the third switch, the fourth switch, and the fifth switch is a transistor.

3. The circuit of claim 2, wherein at least one of the first switch, the second switch, the third switch, the fourth switch, and the fifth switch is a MOSFET.

4. The circuit of claim 2, wherein at least one of the first switch, the second switch, the third switch, the fourth switch, and the fifth switch is controlled by a controller.

5. The circuit of claim 1, wherein:

when the circuit is in a first state:

the first switch is closed;

the second switch is open;

the third switch is open;

the fourth switch is closed; and is

The fifth switch is open; and

when the circuit is in a second state:

the first switch is closed;

the second switch is open;

the third switch is closed;

the fourth switch is open; and is

The fifth switch is closed.

6. The circuit of claim 5, wherein:

when the circuit is in a third state:

the first switch is open;

the second switch is closed;

the third switch is open;

the fourth switch is closed; and is

The fifth switch is open; and

when the circuit is in a fourth state:

the first switch is open;

the second switch is open;

the third switch is closed;

the fourth switch is open; and is

The fifth switch is closed.

7. The circuit of claim 1, further comprising:

a sixth switch having a first side and a second side, wherein the first side thereof is connected to the second side of the inductor;

a seventh switch having a first side and a second side, wherein the first side thereof is connected to the input voltage;

a third capacitor having a first side and a second side, wherein the first side thereof is connected to the second side of the seventh switch;

an eighth switch having a first side and a second side, wherein the first side thereof is connected to the second side of the sixth switch;

a ninth switch having a first side and a second side, wherein the first side thereof is connected to the second side of the eighth switch; and

a tenth switch having a first side and a second side, wherein the first side thereof is connected to the second side of the third capacitor and the second side of the ninth switch, and wherein the second side thereof is coupled to the voltage source.

8. The circuit of claim 7, wherein

When the circuit is in a first state:

the first switch is open;

the second switch is closed;

the third switch is open;

the fourth switch is closed;

the fifth switch is open;

the sixth switch is open;

the seventh switch is open;

the eighth switch is closed;

the ninth switch is open; and is

The tenth switch is closed; and

when the circuit is in a second state:

the first switch is open;

the second switch is open;

the third switch is closed;

the fourth switch is open;

the fifth switch is closed;

the sixth switch is open;

the seventh switch is closed;

the eighth switch is open;

the ninth switch is closed; and is

The tenth switch is open.

9. The circuit of claim 8, wherein:

when the circuit is in a third state:

the first switch is closed;

the second switch is open;

the third switch is open;

the fourth switch is closed;

the fifth switch is open;

the sixth switch is open;

the seventh switch is open;

the eighth switch is closed;

the ninth switch is open; and is

The tenth switch is closed;

when the circuit is in a fourth state:

the first switch is open;

the second switch is open;

the third switch is open;

the fourth switch is closed;

the fifth switch is open;

the sixth switch is closed;

the seventh switch is open;

the eighth switch is closed;

the ninth switch is open; and is

The tenth switch is closed;

when the circuit is in a fifth state:

the first switch is open;

the second switch is open;

the third switch is closed;

the fourth switch is open;

the fifth switch is closed;

the sixth switch is closed;

the seventh switch is open;

the eighth switch is open;

the ninth switch is closed; and is

The tenth switch is open; and

when the circuit is in a sixth state:

the first switch is closed;

the second switch is open;

the third switch is closed;

the fourth switch is open;

the fifth switch is closed;

the sixth switch is open;

the seventh switch is open;

the eighth switch is open;

the ninth switch is closed; and is

The tenth switch is open.

10. The circuit of claim 1, wherein the circuit is implemented in an integrated circuit.

11. The circuit of claim 1, wherein the circuit comprises at least one of the first capacitor, the second capacitor, and the inductor.

12. The circuit of claim 11, wherein the circuit is implemented in an integrated circuit.

13. The circuit of claim 1, wherein the circuit comprises at least two of the first capacitor, the second capacitor, and the inductor.

14. The circuit of claim 13, wherein the circuit is implemented in an integrated circuit.

15. The circuit of claim 1, wherein the circuit comprises the first capacitor, the second capacitor, and the inductor.

16. The circuit of claim 15, wherein the circuit is implemented in an integrated circuit.