TWI674493B - Low-dropout shunt voltage regulator - Google Patents

Abstract

The invention provides a low dropout shunt regulator, which includes a first current mirror module, a second current mirror module, and an output module. The first terminal of the first current mirror module is electrically connected to the input voltage. The first current mirror module has a high output impedance. The first terminal of the second current mirror module is electrically connected to the second terminal of the first current mirror module. Terminal, the second terminal of the second current mirror module is electrically connected to a reference voltage; the output terminal of the output module is electrically connected to the third terminal of the first current mirror module, the output terminal of the output module and the first terminal The second current mirror module is electrically connected to each other, and the second terminal of the output module is electrically connected to the reference voltage.

Description

Low dropout shunt regulator

The invention relates to a low dropout shunt regulator, and in particular to a low dropout shunt regulator having a low current change rate in an input voltage range.

In the voltage stabilization circuit, the low drop linear regulator is a circuit that provides a stable voltage and current, and can receive a wide range of input voltages, such as 5V ~ 30V.

However, because the range of the input voltage is quite large, the low-dropout linear regulator needs to provide a stable output current. When the input voltage is a high voltage, the general low-dropout linear regulator mainly uses a current mirror circuit as the current. Source, while the traditional current mirror switching element does not have a high output impedance, relatively, the energy consumed in it will also increase accordingly.

Therefore, it is an important issue in the industry to provide a voltage regulator with a high output impedance current source.

In view of this, an embodiment of the present invention discloses a low dropout shunt regulator for converting an input voltage to an output voltage. The low dropout shunt regulator includes a first current mirror module including a first Terminal, a second terminal, and a third terminal, wherein the first terminal of the first current mirror module is electrically connected to the input voltage, and the first current mirror module has a high output impedance; a second current The mirror module includes a first end and a second end, wherein the first end of the second current mirror module is electrically connected to the first The second end of the current mirror module, the second end of the second current mirror module is electrically connected to a reference voltage; and an output module including an output terminal, a first terminal, and a second terminal, The output terminal of the output module is electrically connected to the third terminal of the first current mirror module, and the output terminal and the first terminal of the output module are electrically connected to the second current mirror module, respectively. The second terminal of the output module is electrically connected to the reference voltage.

In summary, the low dropout shunt regulator in the present invention uses a first current mirror switch, a third current mirror switch combined with a low voltage process, and a second current mirror switch and a fourth current mirror switch with a high voltage process. The output impedance of the current mirror circuit can reduce the current change caused by the large input voltage range, and can also reduce the internal energy consumption of the regulator. In addition, the combination of the current mirror switch with a low-voltage process and the current mirror switch with a high-voltage process can more flexibly adjust the chip layout.

In order to make the above features and advantages of the present invention more comprehensible, preferred embodiments are described below in detail with the accompanying drawings, as follows.

1‧‧‧ Low Dropout Shunt Regulator

11‧‧‧The first current mirror module

12‧‧‧Second current mirror module

13‧‧‧Output module

14‧‧‧Activation module

11-N1‧‧‧ the first end of the first current mirror module

11-N2‧‧‧ the second end of the first current mirror module

11-N3 The third end of the first current mirror module

12-N1‧‧‧ the first end of the second current mirror module

12-N2‧‧‧Second end of the second current mirror module

13-N1‧‧‧ the first end of the output module

13-N2‧‧‧Second end of output module

14-N1‧‧‧ the first end of the startup module

14-N2‧‧‧The second end of the startup module

14-N3‧‧‧The third end of the startup module

Out‧‧‧output

MP1‧‧‧The first current mirror switch

MP2‧‧‧Second Current Mirror Switch

MP3‧‧‧Third Current Mirror Switch

MP4‧‧‧ Fourth current mirror switch

MO1‧‧‧First output switch

MO2‧‧‧Second Output Switch

MO3‧‧‧Third output switch

MO4‧‧‧Fourth output switch

MN5‧‧‧Fifth current mirror switch

MN6‧‧‧The sixth current mirror switch

SWN1‧‧‧First start switch

SWN2‧‧‧Diode Connection Transistor

SWN3‧‧‧Third start switch

Ibias‧‧‧External current source

R1‧‧‧first impedance

R2‧‧‧Second impedance

R3‧‧‧Third impedance

SW1‧‧‧The first switch

I‧‧‧ dotted line

II‧‧‧solid line

V _CC ‧‧‧ Input voltage

Vee‧‧‧Reference voltage

FIG. 1 is a schematic diagram of a low dropout shunt regulator according to an embodiment of the present invention.

FIG. 2 is a schematic circuit diagram of the first current mirror module in FIG. 1.

FIG. 3 is a schematic circuit diagram of a second current mirror module in FIG. 1.

FIG. 4 is a schematic circuit diagram of the output module in FIG. 1.

FIG. 5 is a schematic circuit diagram of the startup module in FIG. 1.

FIG. 6 is a schematic diagram of the voltage and current of the first current mirror module of FIG. 1.

Various exemplary embodiments will be described more fully hereinafter with reference to the accompanying drawings, in which some exemplary embodiments are shown. However, the inventive concept may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. In the In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. Similar numbers always indicate similar components.

It should be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. Thus, a first element discussed below may be referred to as a second element without departing from the teachings of the inventive concept. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

In the following, the voltage regulator will be described with at least one embodiment in conjunction with the drawings. However, the following embodiments are not intended to limit the disclosure.

The following description of the pin positions of each switching element is based on the marked numbers of each pin position.

[An embodiment of the low-dropout shunt regulator of the present invention]

Please refer to FIGS. 1 to 5, which are schematic diagrams of a low dropout shunt regulator according to an embodiment of the present invention. FIG. 2 is a schematic circuit diagram of the first current mirror module in FIG. 1. FIG. 3 is a schematic circuit diagram of a second current mirror module in FIG. 1. FIG. 4 is a schematic circuit diagram of the output module in FIG. 1. FIG. 5 is a schematic circuit diagram of the startup module in FIG. 1.

The low dropout shunt regulator 1 includes a first current mirror module 11, a second current mirror module 12, an output module 13, and a startup module 14.

In this embodiment, the low-dropout shunt regulator 1 is a low-dropout voltage regulator for converting an input voltage V _CC into an output voltage V _OUT . In this embodiment, the range of the input voltage V _CC may be 0V ~ 40V, for example: 4.5V ~ 30V, which can be adjusted according to actual needs, which is not limited in the present invention.

In this embodiment, the first current mirror module 11 includes a first terminal 11-N1, a second terminal 11-N2, and a third terminal 11-N3. The first terminal 11-N1 of the first current mirror module 11 is electrically connected to the input voltage V _CC .

The second current mirror module 12 also includes a first terminal 12-N1 and a second terminal. 12-N2. The first terminal 12-N1 of the second current mirror module 12 is electrically connected to the second terminal 11-N2 of the first current mirror module 11. A second terminal 12-N2 of the second current mirror module 12 is electrically connected to a reference voltage Vee. In this embodiment, the reference voltage Vee is a ground potential, however, it can be designed and adjusted according to actual needs, which is not limited in the present invention.

The output module 13 includes an output terminal Out, a first terminal 13-N1, and a second terminal 13-N2. The output terminal Out of the output module 13 is electrically connected to the third terminal 11-N3 of the first current mirror module 11, and the output terminal Out and the first terminal 13-N1 of the output module 13 are electrically connected to the second current mirror module In group 12, the second terminal 13-N2 of the output module 13 is electrically connected to the reference voltage Vee. The regulator 1 provides an output voltage V _OUT through an output terminal Out of the output module 13. The output voltage V _OUT can be a fixed voltage or a variable voltage, and can be designed and adjusted according to actual needs, which is not limited in the present invention.

The startup module 14 includes a first end 14-N1, a second end 14-N2, and a third end 14-N3. The first terminal 13-N1 of the startup module 13 is electrically connected to the input voltage V _CC , the second terminal 14-N2 of the startup module 14 is electrically connected to the reference voltage Vee, and the third terminal 14-N3 of the startup module 14 is electrically Connected to the first end 12-N1 of the second current mirror module 12.

The third terminal 14-N3 of the starting module 14 is electrically connected to the second terminal 11-N2 of the first current mirror module 11 through a first impedance R1. The output terminal Out of the output module 13 is electrically connected to the second current mirror module 12 through a second impedance R2.

Referring to FIG. 2, the first current mirror module 11 includes a first current mirror switch MP1, a second current mirror switch MP2, a third current mirror switch MP3, and a fourth current mirror switch MP4.

The first current mirror switch MP1 has a first terminal, a second terminal, and a third terminal. The first terminal of the first current mirror switch MP1 is electrically connected to the first terminals 11-N1 of the first current mirror module 11. The second current mirror switch MP2 has a first terminal, a second terminal, and a third terminal. The first terminal of the second current mirror switch MP2 is electrically connected to the third terminal of the first current mirror switch MP1, and the second terminal of the second current mirror switch MP2 is electrically connected to the second terminal of the first current mirror switch MP1 and the first terminal. The third terminal of the two current mirror switch MP2. First The third terminal of the two current mirror switch MP2 is electrically connected to the second terminal 11-N2 of the first current mirror module 11. The third current mirror switch MP3 has a first terminal, a second terminal, and a third terminal. The first terminal of the third current mirror switch MP3 is electrically connected to the first terminals 11-N1 of the first current mirror module 11. The second terminal of the third current mirror switch MP3 is electrically connected to the second terminal of the first current mirror switch MP1 and the second terminal of the second current mirror switch MP2. The fourth current mirror switch MP4 has a first terminal, a second terminal, and a third terminal. A first terminal of the fourth current mirror switch MP4 is electrically connected to a third terminal of the third current mirror switch MP3. The second terminal of the fourth current mirror switch MP4 is electrically connected to the second terminal of the third current mirror switch MP3, and the third terminal of the fourth current mirror switch MP4 is electrically connected to the third terminal 11- of the first current mirror module 11. N3.

In this embodiment, the first current mirror switch MP1, the second current mirror switch MP2, the third current mirror switch MP3, and the fourth current mirror switch MP4 constitute a current mirror circuit, which receives the input voltage V _CC and provides a stable current to Output Out.

In this embodiment, the first current mirror switch MP1, the second current mirror switch MP2, the third current mirror switch MP3, and the fourth current mirror switch MP4 are a P-type metal oxide semiconductor field effect transistor (P-type Metal Oxide Semiconductor Field Effect Transistor). In this embodiment, the first current mirror switch MP1 and the third current mirror switch MP3 are metal oxide semiconductor field effect transistors in a low voltage process. The second current mirror switch MP2 and the fourth current mirror switch MP4 are metal oxide semiconductor field effect transistors in a high voltage process. In addition, the first current mirror switch MP1 and the second current mirror switch MP2 may also be a composite transistor. The third current mirror switch MP3 and the fourth current mirror switch MP4 may be a composite transistor, which is not limited in the present invention.

In this embodiment, the first current mirror switch MP1, the third current mirror switch MP3 of the low voltage process and the second current mirror switch MP2, the fourth current mirror switch MP4 of the high voltage process are combined to enable the first The current mirror module 11 has a high output impedance. Therefore, when the voltage regulator 1 changes from a low voltage to a high voltage in the input voltage range (4.5V ~ 30V), the output current change of the first current mirror module 11 can be reduced accordingly.

Referring to FIG. 3, the second current mirror module 12 includes a first switch SW1, a fifth current mirror switch MN5, and a sixth current mirror switch MN6. The first switch SW1 has a first terminal, a second terminal, and a third terminal. The first terminal of the first switch SW1 is electrically connected to the first terminals 12 -N1 of the second current mirror module 12. The fifth current mirror switch MN5 has a first terminal, a second terminal, and a third terminal. A first terminal of the fifth current mirror switch MN5 is electrically connected to an external current source Ibias and a second terminal of the fifth current mirror switch MN5, and a third terminal of the fifth current mirror switch MN5 is electrically connected to the reference voltage Vee. The sixth current mirror switch MN6 has a first terminal, a second terminal, and a third terminal. A first terminal of the sixth current mirror switch MN6 is electrically connected to a third terminal of the first switch SW1. The second terminal of the sixth current mirror switch MN6 is electrically connected to the second terminal of the fifth current mirror switch MN5. The third terminal of the sixth current mirror switch MN6 is electrically connected to the reference voltage Vee.

In this embodiment, the fifth current mirror switch MN5 and the sixth current mirror switch MN6 form a current mirror circuit.

Referring to FIG. 4, the output module 13 includes a first output switch MO1, a second output switch MO2, a third output switch MO3, and a fourth output switch MO4.

The first output switch MO1 has a first terminal, a second terminal, and a third terminal. The first terminal of the first output switch MO1 is electrically connected to the output terminal Out of the output module 13. The second terminal of the first output switch MO1 is electrically connected to the third terminal of the first output switch MO1. The second output switch MO2 has a first terminal, a second terminal, and a third terminal. A first terminal of the second output switch MO2 is electrically connected to a third terminal of the first output switch MO1. The third output switch MO3 has a first terminal, a second terminal, and a third terminal. The first terminal of the third output switch MO3 is electrically connected to the third terminal of the second output switch MO2, and the second terminal of the third output switch MO3 is electrically connected to the second terminal of the second output switch MO2. The third terminal of the third output switch MO3 is electrically connected to the reference voltage Vee. The fourth output switch MO4 has a first terminal, a second terminal, and a third terminal. The first terminal of the fourth output switch MO4 is electrically connected to the output terminal Out of the output module 13. The second terminal of the fourth output switch MO4 is electrically connected to the third terminal of the second output switch MO2 and The first terminal of the third output switch MO3. The third terminal of the fourth output switch MO4 is electrically connected to the reference voltage Vee. The second terminal of the second output switch MO2 and the second terminal of the third output switch MO3 are electrically connected to the second terminal of the fifth current mirror switch MN5 of the second current mirror module 12 and the second terminal of the sixth current mirror switch MN6. end.

In addition, the output terminal Out of the output module 13 is electrically connected to the second terminal of the first switch SW1 of the second current mirror module 12 through a second impedance R2. That is, in the present embodiment, the first switch SW1 is the output terminal Out of the output voltage V _OUT as the bias voltage, the output voltage V _OUT is a stable voltage, a first switch SW1 is able to ensure in a low input It can also be turned on continuously at the voltage V _CC .

In this embodiment, the first output switch MO1, the second output switch MO2 of the output module 13 and the fifth current source switch MN5 of the second current mirror module 12 are used as the mains for establishing the output voltage V _OUT of the regulator 1. element.

In addition, the second output switch MO2 and the third output switch MO3 constitute an AB class amplifier for controlling the opening and closing of the fourth output switch MO4 to control the level of the output voltage V _OUT at the output terminal Out.

Referring to FIG. 5, the startup module 14 includes a first startup switch SWN1, a diode-connected transistor SWN2, and a third startup switch SWN3.

The first start switch SWN1 has a first terminal, a second terminal, and a third terminal. The first terminal of the first startup switch SWN1 is electrically connected to the first terminal 14-N1 of the startup module 14 through a third impedance R3, and the second terminal of the first startup switch SWN1 is electrically connected to the second current mirror module. 12 The second end of the first switch SW1. The third terminal of the first startup switch SWN1 is electrically connected to the second terminal 14-N2 of the startup module 14.

The diode-connected transistor SWN2 has a first terminal, a second terminal, and a third terminal. The first terminal of the diode-connected transistor SWN2 is electrically connected to the first terminal of the first start switch SWN1 and the second terminal of the diode-connected transistor SWN2, and the diode is connected to the third terminal of the transistor SWN2. The second terminal 14-N2 of the starting module 14 is electrically connected.

The third start switch SWN3 has a first terminal, a second terminal, and a third terminal. The first terminal of the third startup switch SWN3 is electrically connected to the third terminal of the startup module 14 14-N3. The second terminal of the third startup switch SWN3 is electrically connected to the first terminal of the first startup switch SWN1 and the first terminal of the diode SWN2, and the third terminal of the third startup switch SWN3 is electrically connected to the startup module. The second end of 14 is 14-N2. In this embodiment, the first terminal of the third start switch SWN3 is electrically connected to the second terminal 11-N2 of the first current mirror module through the first impedance R1.

In this embodiment, the first startup switch SWN1, the diode-connected transistor SWN2, and the third startup switch SWN3 function as a startup regulator 1. In other embodiments, other circuits may also be used to start the regulator 1, which is not limited in the present invention.

Please refer to FIG. 6, which is a schematic diagram of the voltage and current of the first current mirror module of FIG. 1.

The dashed line I is a low-dropout shunt regulator of the prior art. The current mirror module only has a single-order current mirror switch. In the input voltage range, the output impedance corresponding to the current change curve of the input voltage and the output impedance. Embodiments of the Invention The low-dropout shunt regulator of the first current mirror module having a high output impedance current source has a current curve corresponding to the input voltage in the input voltage range. The low-dropout shunt regulator 1 of the first current mirror module 11 with high output impedance according to the embodiment of the present invention has a low degree of current change.

[Possible effects of the embodiments]

In summary, the low dropout shunt regulator in the present invention uses a first current mirror switch, a third current mirror switch combined with a low voltage process, and a second current mirror switch and a fourth current mirror switch with a high voltage process. The output mirror's current mirror circuit reduces the current change caused by the large input voltage range, and can also reduce the internal energy consumption of the low dropout shunt regulator. In addition, the combination of the current mirror switch with a low-voltage process and the current mirror switch with a high-voltage process can more flexibly adjust the chip layout.

The above description is only an embodiment of the present invention, and is not intended to limit the patent scope of the present invention.

Claims (9)

A low dropout shunt regulator is used to convert an input voltage to an output voltage. The low dropout shunt regulator includes a first current mirror module including a first terminal, a second terminal, and a third terminal. Terminal, wherein the first terminal of the first current mirror module is electrically connected to the input voltage; a second current mirror module includes a first terminal and a second terminal, wherein the second current mirror module The first terminal is electrically connected to the second terminal of the first current mirror module, and the second terminal of the second current mirror module is electrically connected to a reference voltage; an output module includes an output terminal, A first end and a second end, wherein the output end of the output module is electrically connected to the third end of the first current mirror module, and the output end and the first end of the output module are electrically Connected to the second current mirror module, the second terminal of the output module is electrically connected to the reference voltage; and a startup module including a first terminal, a second terminal, and a third terminal, wherein the startup The first terminal of the module is electrically connected to the input voltage, and the second terminal of the startup module is electrically connected. Connected to the reference voltage, the third terminal of the starting module is electrically connected to the first terminal of the second current mirror module; wherein the first current mirror module includes a first current mirror switch having a A first end, a second end, and a third end, wherein the first end of the first current mirror switch is electrically connected to the first end of the first current mirror module; a second current mirror switch, There is a first terminal, a second terminal, and a third terminal. The first terminal of the second current mirror switch is electrically connected to the third terminal of the first current mirror switch. The second terminal is electrically connected to the second terminal of the first current mirror switch and the third terminal of the second current mirror switch, and the third terminal of the second current mirror switch is electrically connected to the first current mirror mode. The second end of the group; a third current mirror switch having a first end, a second end, and a third end, the first end of the third current mirror switch is electrically connected to the first current mirror mode Set of the A first end, the second end of the third current mirror switch is electrically connected to the second end of the first current mirror switch and the second end of the second current mirror switch; and a fourth current mirror switch, The first terminal has a first terminal, a second terminal, and a third terminal. The first terminal of the fourth current mirror switch is electrically connected to the third terminal of the third current mirror switch. The second terminal is electrically connected to the second terminal of the third current mirror switch, and the third terminal of the fourth current mirror switch is electrically connected to the third terminal of the first current mirror module. For example, the low-dropout shunt regulator of the first patent application scope, wherein the third terminal of the starting module is electrically connected to the second terminal of the first current mirror module through a first impedance. For example, the low-dropout shunt regulator of the first patent application range, wherein the output terminal of the output module is electrically connected to the first terminal of the second current mirror module through a second impedance. For example, the low-dropout shunt regulator of the first patent application scope, wherein the second current mirror module includes: a first switch having a first terminal, a second terminal, and a third terminal, wherein The first end of the first switch is electrically connected to the first end of the second current mirror module; a fifth current mirror switch has a first end, a second end, and a third end, and the fifth The first terminal of the current mirror switch is electrically connected to an external current source and the second terminal of the fifth current mirror switch, and the third terminal of the fifth current mirror switch is electrically connected to the reference voltage; a sixth current The mirror switch has a first end, a second end, and a third end. The first end of the sixth current mirror switch is electrically connected to the third end of the first switch. The second terminal is electrically connected to the second terminal of the fifth current mirror switch, and the third terminal of the sixth current mirror switch is electrically connected to the reference voltage. For example, the low-dropout shunt regulator of patent application No. 4 wherein the output mode The set includes: a first output switch having a first end, a second end, and a third end, wherein the first end of the first output switch is electrically connected to the output end of the output module, and The second terminal of the first output switch is electrically connected to the third terminal of the first output switch; a second output switch has a first terminal, a second terminal, and a third terminal, wherein the second terminal The first terminal of the output switch is electrically connected to the third terminal of the first output switch; a third output switch has a first terminal, a second terminal, and a third terminal, wherein the third output switch The first terminal of the third output switch is electrically connected to the third terminal of the second output switch, the second terminal of the third output switch is electrically connected to the second terminal of the second output switch, and the third terminal of the third output switch The third terminal is electrically connected to the reference voltage; a fourth output switch has a first terminal, a second terminal, and a third terminal, wherein the first terminal of the fourth output switch is electrically connected to the output mode. The output end of the group, the second end of the fourth output switch is electrically connected to the second output Off the third terminal and the third output terminal of the first switch, the third output terminal of the fourth switch is connected to the reference voltage. For example, the low-dropout shunt regulator of item 5 of the patent application, wherein the second end of the second output switch and the second end of the third output switch are electrically connected to the second current mirror module. The second end of the fifth current mirror switch and the second end of the sixth current mirror switch. For example, the low-dropout shunt regulator of item 6 of the patent application, wherein the output terminal is electrically connected to the second terminal of the first switch of the second current mirror module through a second impedance. For example, the low-dropout shunt regulator of item 7 of the patent application scope, wherein the starting module includes: a first starting switch having a first terminal, a second terminal, and a third terminal, wherein the first The first terminal of the start switch is electrically connected to the first terminal through a third impedance. The first end of the startup module, the second end of the first startup switch is electrically connected to the second end of the first switch of the second current mirror module, and the third end of the first startup switch The terminal is electrically connected to the second end of the startup module; a diode-connected transistor has a first terminal, a second terminal, and a third terminal, wherein the diode is connected to the transistor. The first terminal is electrically connected to the first terminal of the first start switch and the second terminal of the diode-connected transistor, and the third terminal of the diode-connected transistor is electrically connected to the start. The second end of the module; and a third startup switch having a first end, a second end, and a third end, wherein the first end of the third startup switch is electrically connected to the startup module The third end of the third start switch, the second end of the third start switch is electrically connected to the first end of the first start switch and the first end of the diode-connected transistor, and the third end of the third start switch The third terminal is electrically connected to the two terminals of the startup module. For example, the low-dropout shunt regulator of item 1 of the patent scope, wherein the first current mirror switch and the third current mirror switch are respectively a P-type metal oxide semiconductor field effect transistor with a low voltage process. The two current mirror switches and the fourth current mirror switch are respectively a P-type metal oxide semiconductor field effect transistor with a high voltage process.