CN117134587B - Self-calibration zero-crossing current detection circuit of switch power supply chip and switch power supply chip - Google Patents
Self-calibration zero-crossing current detection circuit of switch power supply chip and switch power supply chip Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0009—Devices or circuits for detecting current in a converter
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
- G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
- G01R19/16571—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing AC or DC current with one threshold, e.g. load current, over-current, surge current or fault current
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/175—Indicating the instants of passage of current or voltage through a given value, e.g. passage through zero
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/087—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current for dc applications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/14—Arrangements for reducing ripples from dc input or output
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
- H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
The invention provides a self-calibration zero-crossing current detection circuit of a switching power supply chip and the switching power supply chip, wherein the detection circuit comprises: the device comprises an SW port detection module, a zero-crossing detection calculation module, a zero-crossing detection calibration module and a zero-crossing comparison module which are connected in sequence; the SW port detection module is used for detecting the voltage of the SW node when the lower pipe of the switching power supply chip is turned off every time, judging the level of the voltage of the SW node twice at two moments in dead time after the lower pipe is turned off, and generating two judging state signals; the zero-crossing detection calculation module is used for updating and outputting two judgment state signals when the lower pipe is opened every time; the zero-crossing detection calibration module judges whether the judgment of the zero-crossing detection is accurate according to the output of the zero-crossing detection calculation module, adjusts the trimming value of the next zero-crossing detection and outputs a trimming signal; the zero-crossing comparison module receives the trimming signal, trims the offset voltage, and outputs a zero-crossing current detection signal.
Description
Technical Field
The invention relates to the technical field of integrated circuits, in particular to a self-calibration zero-crossing current detection circuit of a switching power supply chip and the switching power supply chip.
Background
In consumer electronics and automotive electronics, because the requirements of various specifications of electronic components and chips on power supplies are different, the energy comes from the battery terminal, and the battery voltage needs to be boosted or reduced. The power chip is capable of converting an input voltage into an output voltage suitable for operation of the electronic device, and thus has been used in consumer electronics, industrial electronics, and automotive electronics in a ubiquitous manner.
In an automobile electronic chip, the input end is usually battery voltage, the voltage range is about 8 v-20 v, the power consumption end is usually an LED lamp bead, the working voltage range of the sensor chip, the interface chip, the main control chip and the like is 2 v-12 v, so that the BUCK (BUCK converter) chip is required to reduce the voltage of the battery end to the rated working voltage of other electronic components to supply power. In practical applications, the output load of the DC-DC conversion chip is not a fixed current, and the load current may fluctuate greatly as the system is in different operations. Taking a BUCK converter as an example, the converter still operates in an inductor Current Continuous Mode (CCM) under light load, and when the down tube of the BUCK is turned on, a negative inductor current flows through the down tube, which results in reduced efficiency. Many DC-DC converters therefore operate in inductor current discontinuous mode (DCM) at light load, i.e. turn off the down tube when the inductor current is 0.
In order to avoid reducing the working efficiency of the DC-DC converter when a larger negative current flows through the power tube in DCM mode, for example, a BUCK converter is usually added with an inductor current zero-crossing detection comparison circuit, and a common scheme is shown in fig. 1:
REG_TOP is the output constant voltage modulation module of BUCK circuit, which is used to output the driving signal to the driving module DRIVER by PWM modulation, and the module drives the upper tube M1 (power switch tube) and the lower tube M2 (power switch tube) to finally generate stable output voltage V OUT . When the circuit is operated in DCM mode, the zero-crossing comparator ZCD_COMP will detect the voltages across SW and PGND when the down tube M2 is ON (LS_ON_ST=1), when VSW>VPGND, the current of the lower tube M2 is from SW to PGND, the inductance current is negative, at this time, the zero-crossing comparator outputs zcd_st=1, and the signal controls the driving module DRIVER to turn off the lower tube M2, so that the BUCK works in DCM mode.
However, this solution has the following drawbacks in the application of the power chip:
1. in the inductance current zero-crossing detection comparison structure in this way, the precision of zero-crossing detection depends on the precision of the zero-crossing comparator zcd_comp, and if the offset voltage of the zero-crossing comparator is Vos, the zero-crossing detection point of the zero-crossing comparator is izcd=vos/rds_on_m2. Normally, the on-resistance rds_on_m2 of the down tube M2 is relatively small, which is in the order of tens of milliohms, so that errors introduced by the conventional zero-crossing comparator cannot be ignored, if the offset of the zero-crossing detection point is biased to negative current, larger efficiency loss exists, and the SW node has larger overshoot when the down tube M2 is turned off; if the offset of the zero crossing point is biased towards positive current, then freewheeling will occur through its body diode when the lower tube M2 is turned off, which will have some loss of efficiency.
2. In order to solve the problem that the zero-crossing comparator is too large in offset, a trimming unit TRIM_CELL is added in a traditional zero-crossing detection circuit, and the offset voltage of the comparator ZCD_COMP is trimmed when a chip leaves a factory through the TRIM_BUS, so that the offset voltage meets the precision requirement. However, the scheme can increase the test time of the chip when leaving the factory, and the cost of the chip is increased.
3. In order to ensure that the zero-crossing comparator has a faster response speed, the current setting of the traditional zero-crossing comparator is larger, and the output load of the BUCK is light load when the chip works in DCM, so that the efficiency requirement is higher, and the larger module power consumption does not meet the requirement of a high-performance power supply on the efficiency.
Therefore, the inductor current zero-crossing detection comparison circuit of the traditional switching power supply chip cannot meet the requirements of the power supply chip for high efficiency, high performance and low cost in practical application.
Disclosure of Invention
The invention aims to provide a self-calibration zero-crossing current detection circuit of a switching power supply chip and the switching power supply chip, which can solve the problems that when the switching power supply chip is in a light-load DCM working mode, reverse current flows into the chip due to inaccurate detection of zero current points of inductive current, so that light-load efficiency is reduced, and output ripple is overlarge.
In order to achieve the above object, the present invention provides a self-calibration zero-crossing current detection circuit of a switching power supply chip, comprising:
the device comprises an SW port detection module, a zero-crossing detection calculation module, a zero-crossing detection calibration module and a zero-crossing comparison module which are connected in sequence;
the SW port detection module comprises two input ends and two output ends, wherein one input end is used for collecting the voltage of the SW node, the other input end is used for inputting the on/off state signal of the lower pipe of the switch power supply chip, the SW port detection module is used for detecting the voltage of the SW node when the lower pipe of the switch power supply chip is turned off each time, and judging the level of the voltage of the SW node twice at two moments in dead time after the lower pipe is turned off, so as to generate two judging state signals, and the two judging state signals are output from the two output ends respectively;
the zero-crossing detection calculation module is used for updating and outputting the two judgment state signals when the lower pipe is opened every time;
the zero-crossing detection calibration module judges whether the judgment of the zero-crossing detection is accurate according to the output of the zero-crossing detection calculation module, adjusts the trimming value of the next zero-crossing detection and outputs a trimming signal;
the zero-crossing comparison module receives the trimming signal and trims the offset voltage; and outputting a zero-crossing current detection signal representing whether the inductance current of the switching power supply chip crosses zero or not according to the magnitude relation between the power ground potential of the switching power supply chip and the voltage of the SW node.
In an alternative, the SW port detection module includes: the device comprises a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube, a first inverter, a second inverter, a third inverter, a first trigger, a second trigger and a delay unit;
the drain electrode of the first MOS tube is used for inputting the voltage of the SW node, the grid electrode of the first MOS tube is connected with a voltage source, the source electrode of the first MOS tube is connected with the drain electrode of the second MOS tube, the grid electrode of the second MOS tube is connected with the output of the third inverter, and the input of the third inverter is used for receiving the state signal of the on/off state of the lower tube; the source electrode of the second MOS tube is connected with the drain electrode of the third MOS tube, and the source electrode of the third MOS tube is grounded; the grid electrode of the third MOS tube is connected with the grid electrode of the fourth MOS tube, the source electrode of the fourth MOS tube is grounded, the drain electrode of the fourth MOS tube is connected with a voltage source, and the drain electrode of the fourth MOS tube is in short circuit with the grid electrode;
the input end of the first inverter is connected with the source electrode of the first MOS tube, and the output end of the first inverter is connected with the input end of the second inverter; the output end of the second inverter is connected with the input ends of the first trigger and the second trigger, and the output end of the first trigger outputs a first judgment state signal; the output end of the second trigger outputs a second judging state signal;
the output signal of the third inverter is used as the clock signal of the first trigger, and the output signal of the third inverter is delayed by the delay unit and then used as the clock signal of the second trigger.
In an alternative, the zero crossing comparison module includes: the device comprises a comparator, a trigger, a NAND gate, an inverter, a first resistor, a second resistor and a trimming resistor unit;
one end of the trimming resistor unit is connected to the power ground, the other end of the trimming resistor unit is connected to one end of the second resistor, and the other end of the second resistor is connected to the negative electrode input end of the comparator and the power supply;
one end of the first resistor is connected with the SW node, and the other end of the first resistor is connected with the positive input end of the comparator and the power supply;
the trimming resistor unit receives the trimming signal of the zero-crossing detection calibration module, and trims the offset voltage of the comparator by adjusting the resistance value of the trimming resistor unit;
the input end of the trigger is connected with a power supply, and the state signal of the on/off state of the down tube is used as a clock signal of the trigger;
the output end of the comparator and the output end of the trigger are used as two output ends of the NAND gate, the output end of the NAND gate is connected with the input end of the inverter, and the output end of the inverter outputs the zero-crossing current detection signal.
In an alternative, the zero crossing comparison module includes: the comparator, the trimming resistor unit and the AND gate;
the trimming resistor unit comprises a plurality of trimming resistors which are connected in series, one end of the trimming resistor unit is connected with the power ground, and the other end of the trimming resistor unit is connected with the negative electrode input end of the comparator;
the two input ends of the AND gate are respectively used for inputting the output signal of the comparator and the on/off state signal of the lower pipe;
the AND gate outputs the zero-crossing current detection signal.
The invention also provides a switching power supply chip which comprises the self-calibration zero-crossing current detection circuit.
The invention has the beneficial effects that:
according to the self-calibration zero-crossing current detection circuit, the zero crossing point of the inductance current can be detected cycle by cycle when the switching power supply chip works, and the self calibration is performed in real time, so that the energy conversion efficiency of the chip is improved, the output ripple wave is reduced, the testing time of the chip when the chip leaves a factory is reduced, and the cost of the chip is reduced.
The invention can detect the current of the upper tube (power switch tube) and the lower tube (power switch tube) at the same time, judge whether the current on the lower tube exceeds the protection threshold value when the lower tube is opened, if the current exceeds the protection threshold value, shield the opening signal of the upper tube from the next period to the beginning, and carry out PWM duty cycle again after waiting for the abnormal release, thereby realizing better protection of the upper tube and the lower tube under the scene of short circuit and instantaneous heavy current.
Drawings
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular descriptions of exemplary embodiments of the invention as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts throughout the exemplary embodiments of the invention.
FIG. 1 is a block diagram of a prior art soft start scheme for BUCK chips.
Fig. 2 is a schematic diagram of a self-calibrating zero-crossing current detection circuit of a switching power supply chip according to an embodiment of the present invention.
FIG. 3 is a waveform diagram of self-calibrating zero-crossing current detection timing of the self-calibrating zero-crossing current detection circuit according to an embodiment of the present invention.
Fig. 4 is a circuit diagram of an SW port detection module according to an embodiment of the present invention.
Fig. 5 is a circuit diagram of a zero-crossing comparison module according to an embodiment of the invention.
Detailed Description
The invention is described in further detail below with reference to the drawings and the specific examples. The advantages and features of the present invention will become more apparent from the following description and drawings, however, it should be understood that the inventive concept may be embodied in many different forms and is not limited to the specific embodiments set forth herein. The drawings are in a very simplified form and are to non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention.
It will be understood that when an element or layer is referred to as being "on," "adjacent," "connected to," or "coupled to" another element or layer, it can be directly on, adjacent, connected, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
Spatially relative terms, such as "under," "below," "beneath," "under," "above," "over," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements or features described as "under" or "beneath" other elements would then be oriented "on" the other elements or features. Thus, the exemplary terms "below" and "under" may include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatially relative descriptors used herein interpreted accordingly.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.
Example 1
Referring to fig. 2 to 5, the present embodiment provides a self-calibrating zero-crossing current detection circuit of a switching power supply chip, including:
the device comprises an SW port detection module SW_DET, a zero-crossing detection calculation module ZCD_CAL, a zero-crossing detection calibration module AUTO_TRIM and a zero-crossing comparison module which are connected in sequence;
the SW port detection module comprises two input ends and two output ends, wherein one input end is used for collecting the voltage of a SW node, the other input end is used for inputting an on/off state signal of a lower pipe of the switch power supply chip, the SW port detection module is used for detecting the voltage of the SW node when the lower pipe M2 of the switch power supply chip is turned off each time, and the level of the voltage of the SW node is judged twice at two moments (t_ls_off and t_ls_off+delta t) in dead time after the lower pipe M2 is turned off, so that two judging state signals (SW_ST1 and SW_ST2) are generated;
the zero-crossing detection calculation module zcd_cal is configured to update and output the two judgment state signals when the lower pipe M2 is opened each time, and output the two judgment state signals from the two output ends respectively;
the zero-crossing detection calibration module AUTO_TRIM judges whether the judgment of the zero-crossing detection is accurate or not according to the PWM control signal and the output of the zero-crossing detection calculation module ZCD_CAL, adjusts the trimming value of the next zero-crossing detection and outputs a trimming signal;
the zero-crossing comparison module receives the trimming signal and trims the offset voltage; and outputting a zero-crossing current detection signal representing whether the inductance current of the switching power supply chip crosses zero or not according to the magnitude relation between the power ground potential of the switching power supply chip and the voltage of the SW node.
Specifically, the switching power supply chip of the present embodiment includes: drive module DRIVER, upper tube M1, lower tube M2, inductor L 1 VBAT represents the input of the switching power supply chip, V OUT Representing the output of the switching power supply chip, load represents the Load. Describing the self-calibration zero-cross current detection circuit of the present embodiment, two judgment status signals sw_st1 and sw_st2 and a status signal ls_on_st of the ON/off state of the down tube M2 are input signals of the zcd_cal module, cal_st<1:0>Is the output signal of the zero crossing detection calculation module zcd_cal. The zero-crossing detection calculation module ZCD_CAL has the function of sampling and updating the state of the inputs SW_ST1 and SW_ST2 at the falling edge of the LS_ON_ST signal, wherein CAL_ST<0>=SW_ST1，CAL_ST<1>=SW_ST2,CAL_ST<1:0>And outputting the zero-crossing detection calibration module AUTO_TRIM to calibrate.
The zero-crossing detection calibration module AUTO_TRIM has an input of the zero-crossing detection calculation module ZCD_CAL and an output CAL_ST <1:0> and a PWM control signal PWM_IN, and outputs a trimming signal TRIM_BUS <3:0>. When cal_st <1:0> =00, the current trim_bus <3:0> value +1 will be set at the rising edge of pwm_in; when cal_st <1:0> =11, the current trim_bus <3:0> value-1 will be set at the rising edge of pwm_in; when cal_st <1:0> =01 or cal_st <1:0> =10, the current trim_bus <3:0> value is maintained when the rising edge of pwm_in comes. The output signal TRIM_BUS <3:0> of the zero-crossing detection calibration module AUTO_TRIM can continuously adjust the offset voltage according to the current feedback, so that the zero-crossing comparison turning point reaches the optimal solution.
Referring to FIG. 3, I L1 Is the current of the inductor of the switching power supply chip, SW is the voltage waveform at the SW node, assuming trim_bus in default mode<3:0>When zero-crossing comparison of the first period is effective, CAL_ST is detected by the SW port detection module SW_DET<1:0>=00, the zero crossing comparison point representing the first cycle is faster, and the comparison point needs to be adjusted to be improved, so that the trim_bus is automatically calibrated to trim_bus in the next cycle<3:0>=1001; when the zero-crossing comparison of the second period is effective, CAL_ST is detected by the SW port detection module SW_DET<1:0>When=11, the zero crossing comparison point representing the second cycle is slow, and the comparison point needs to be adjusted to be lowered, so that the trim_bus is automatically calibrated to trim_bus in the next cycle<3:0>=1000; when the zero-crossing comparison of the third period is effective, CAL_ST is detected by SW_DET<1:0>=10, the zero crossing comparison point representing the third cycle is the optimal solution required, so the value of trim_bus is maintained at the next cycle.
Referring to fig. 4, in the present embodiment, the SW port detection module sw_det includes: the MOS transistor comprises a first MOS transistor MN1, a second MOS transistor MN2, a third MOS transistor MN3 and a fourth MOS transistor MN4, a first inverter INV1, a second inverter INV2, a third inverter INV3, a first trigger DFF1, a second trigger DFF2 and a delay unit Deltat; the drain electrode of the first MOS tube MN1 is used for inputting a voltage waveform of an SW node, the grid electrode of the first MOS tube MN1 is connected with a voltage source VDD, the source electrode of the first MOS tube MN1 is connected with the drain electrode of the second MOS tube MN2, the grid electrode of the second MOS tube MN2 is connected with the output of the third inverter INV3, and the input of the third inverter INV3 is used for receiving a state signal of the lower tube M2 for being turned on/off; the source electrode of the second MOS tube MN2 is connected to the drain electrode of the third MOS tube MN3, and the source electrode of the third MOS tube MN3 is grounded; the grid electrode of the third MOS tube MN3 is connected with the grid electrode of the fourth MOS tube MN4, the source electrode of the fourth MOS tube MN4 is grounded, the drain electrode of the fourth MOS tube MN4 is connected with the voltage source VDD, and the drain electrode of the fourth MOS tube MN4 is in short circuit with the grid electrode; the input end of the first inverter INV1 is connected to the source electrode of the first MOS transistor MN1, and the output end of the first inverter INV1 is connected to the input end of the second inverter INV 2; the output end of the second inverter INV2 is connected to the input ends of the first flip-flop DFF1 and the second flip-flop DFF2, and the output end of the first flip-flop DFF1 outputs a first judgment state signal sw_st1; the output end of the second trigger DFF2 outputs a second judging state signal SW_ST2; the output signal of the third inverter INV3 is used as the clock signal of the first flip-flop DFF1, and the output signal of the third inverter INV3 is delayed by the delay unit and then used as the clock signal of the second flip-flop DFF 2.
At the moment when the lower tube M2 is turned off, ls_on_st=1, at this moment, the second MOS tube MN2 is turned ON, the SW signal is coupled to the junction (sw_sns node) of the first MOS tube and the second MOS tube through the first MOS tube MN1, the level state of the SW signal is judged through the first inverter INV1 and the second inverter INV2, the state is output as a first judgment state signal sw_st1 by the first flip-flop DFF1, after the ls_on_b signal is delayed by the delay unit Δt delay, the ls_on_b signal is delayed by Δt time by the low-to-high signal, the delayed signal is passed through the second flip-flop DFF2, the state of SW at the time of t+Δt is collected, and the output signal-second judgment state signal sw_st2 is generated. In this embodiment, the gate of the first MOS transistor MN1 is connected to the voltage source VDD to enable the first MOS transistor MN1 to be in a conducting state, so that the technical scheme can be applied in a high voltage domain (the voltage source VDD is in a common 5V/3.3V/1.8V power domain, VBAT higher than VDD is a high voltage domain), the SW node can be high voltage, and here the first MOS transistor MN1 can use a high voltage transistor to clamp the sw_sns node, so as to prevent the sw_sns node from being coupled to a device at a later stage of high voltage damage by SW signals.
Referring to fig. 5, in this embodiment, the zero-crossing comparison module includes: comparator ZCD_CMP, flip-flop DFF4, NAND gate NAND1, inverter INV4, first resistor R SNS1 A second resistor R SNS2 Trimming resistor unit TRIM_CELL; in this embodiment, the trimming resistor unit trim_cell includes 4 trimming resistors (the first trimming resistor R respectively) connected in series TRIM0 Second trimming resistor R TRIM1 Third trimming resistor R TRIM2 Fourth trimming resistor R TRIM3 ) And a switch connected in parallel with each trimming resistor, TRIM_BUS<0>To TRIM_BUS<3>In order to control the on-off control signals of the switches, certain resistors are short-circuited by controlling the on-off of the corresponding switches so as to change the resistance value of the whole trimming resistor unit TRIM_CELL. One end of the trimming resistor unit TRIM_CELL is connected to the power ground PGND, and the other end is connected to the second resistor R SNS2 Is one end of the second resistor R SNS2 The other end of the capacitor is connected with the negative input end of the comparator ZCD_CMP and the power supply VDD; the first resistor R SNS1 One end of the (B) is connected with the SW node, and the other end is connected with the positive input end of the comparator ZCD_CMP and the power supply VDD; the trimming resistor unit TRIM_CELL receives the trimming signal of the zero-crossing detection calibration module AUTO_TRIM, and TRIMs the offset voltage of the comparator ZCD_CMP by adjusting the resistance value of the trimming resistor unit TRIM_CELL; the input end of the trigger DFF1 is connected to a power supply VDD, and the on/off state signal of the down tube M2 is used as a clock signal of the trigger DFF 4; the output end of the comparator zcd_cmp and the output end of the trigger DFF4 serve as two output ends of the NAND gate NAND1, the output end of the NAND gate NAND1 is connected to the input end of the inverter INV3, and the output end of the inverter INV4 outputs the zero-crossing current detection signal zcd_cmp_out.
The zero-crossing comparison module detects the voltage of SW when the lower tube M2 is turned on, and judges the inductance current I when the voltage vsw=0 of SW L1 At 0, the comparator toggles high, releasing the zero-crossing current detection signal zcd_cmp_out. In fig. 5, a bias current with isns1=isns2 flows through the first resistor R SNS1 Superimposed on the SW signal, the comparator ZCD CMP has a better bias point. Trimming resistor unit TRIM_CELL is used for receiving trimming signal TRIM_BUS of zero-crossing detection calibration module AUTO_TRIM<3:0>The comparator inversion point is advanced or retarded so that the comparator finds the optimal zero crossing detection inversion signal in the system. In the first flip-flop DFF1, NAND gate NAND1 and first inverter INV1 in fig. 5, the comparator zcd_cmp has a correct output after the down tube M2 is turned on, so that false flip-flop caused by disturbance in other states is avoided.
In another embodiment, the zero crossing comparison module comprises: the comparator, the trimming resistor unit and the AND gate; the trimming resistor unit comprises a plurality of trimming resistors which are connected in series, one end of the trimming resistor unit is connected to the power ground, and the other end of the trimming resistor unit is connected to the negative electrode input end of the comparator; the two input ends of the AND gate are respectively used for inputting the output signal of the comparator and the on/off state signal of the lower pipe; the AND gate outputs the zero-crossing current detection signal.
In the invention, the specific forms of the zero-crossing detection calculation module ZCD_CAL and the zero-crossing detection calibration module AUTO_TRIM can be realized by means of analog components, digital RTL codes, software and the like, and according to the functions of the two modules, the specific implementation modes which can be adopted are known to the skilled person, and the invention utilizes the principles and functions of the two modules in a system and is not limited to the specific implementation modes.
In this embodiment, taking a BUCK converter chip as an example, it can detect the current of the upper tube M1 (high-end power tube) and the lower tube M2 (low-end power tube) at the same time, when the lower tube M2 is turned on, it is determined whether the current on the lower tube M2 exceeds a protection threshold, if so, the PWM duty cycle is re-performed after the next period to the beginning of shielding the upper tube on signal and waiting for the abnormal release, thereby achieving better protection of the power switch tube under the scene of short circuit and instantaneous heavy current.
The self-calibration zero-crossing current detection circuit provided by the invention has the following advantages:
1. independent of the absolute accuracy of the comparator ZCD CMP. The actual effect of zero crossing comparison of the inductance current is collected through the SW port detection module SW_DET, calibration calculation is carried out, the turnover point of the comparator ZCD_CMP can be adjusted by the value of the self-adaptive condition TRIM_BUS, therefore, the requirement on absolute precision of the comparator is reduced, the chip area is reduced, and the power consumption is reduced through self-adaptive calibration.
2. The accuracy of the comparator does not need to be additionally modified when the chip leaves the factory. According to the analysis, the zero-crossing comparison module is self-adaptive cycle-by-cycle trimming when being used by a customer, so that extra trimming is not needed when leaving a factory.
3. Independent of the response time of the comparator itself. The zero-crossing detection comparison is carried out cycle by cycle, the self-adaptive trimming comparison is carried out on the zero-crossing turning point, so that even if the external input and output conditions change, the turning point can be adjusted to an optimal value through one or more cycles, and the problem that the traditional scheme depends on the response speed of the zero-crossing comparator, and extra power consumption is brought is avoided.
4. The self-calibration zero-crossing current detection circuit provided by the invention has the characteristics of high precision, low power consumption, low cost and wide application range, and can be widely applied to a power management chip.
The partial structure of the self-calibration zero-crossing current detection circuit can be manufactured by a semiconductor integrated process.
Example 2
The embodiment provides a switching power supply chip, which comprises the self-calibration zero-crossing current detection circuit in embodiment 1. The switching power supply chip may be a vehicle-mounted switching power supply chip. Referring to fig. 2, the chip may include: constant voltage modulation module REG_TOP, driving module DRIVER, upper tube M1, lower tube M2, inductance L 1 First capacitor C BT And a second capacitor C OUT . The upper tube M1 and the lower tube M2 are power switch tubes. The constant voltage modulation module REG_TOP outputs a driving signal to the driving module DRIVER through PWM modulation, and the control end of the driving module DRIVER is connected with the output of the self-calibration zero-crossing current detection circuit. The specific circuit connection is shown in fig. 2.
The above description is only illustrative of the preferred embodiments of the present invention and is not intended to limit the scope of the present invention, and any alterations and modifications made by those skilled in the art based on the above disclosure shall fall within the scope of the appended claims.
Claims (5)
1. A self-calibrating zero-crossing current detection circuit for a switching power supply chip, comprising:
the device comprises an SW port detection module, a zero-crossing detection calculation module, a zero-crossing detection calibration module and a zero-crossing comparison module which are connected in sequence;
the SW port detection module comprises two input ends and two output ends, wherein one input end is used for collecting the voltage of the SW node, the other input end is used for inputting the on/off state signal of the lower pipe of the switch power supply chip, the SW port detection module is used for detecting the voltage of the SW node when the lower pipe of the switch power supply chip is turned off each time, and judging the level of the voltage of the SW node twice at two moments in dead time after the lower pipe is turned off, so as to generate two judging state signals, and the two judging state signals are output from the two output ends respectively;
the zero-crossing detection calculation module is used for updating and outputting the two judgment state signals when the lower pipe is opened every time;
the zero-crossing detection calibration module judges whether the judgment of the current zero-crossing detection is accurate according to the output of the zero-crossing detection calculation module, adjusts the trimming value of the next zero-crossing detection and outputs a trimming signal;
the zero-crossing comparison module receives the trimming signal and trims the offset voltage; and outputting a zero-crossing current detection signal representing whether the inductance current of the switching power supply chip crosses zero or not according to the magnitude relation between the power ground potential of the switching power supply chip and the voltage of the SW node.
2. The self-calibrating zero-crossing current detection circuit of a switching power supply chip of claim 1, wherein said SW port detection module comprises:
the device comprises a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube, a first inverter, a second inverter, a third inverter, a first trigger, a second trigger and a delay unit;
the drain electrode of the first MOS tube is used for inputting the voltage of the SW node, the grid electrode of the first MOS tube is connected with a voltage source, the source electrode of the first MOS tube is connected with the drain electrode of the second MOS tube, the grid electrode of the second MOS tube is connected with the output of the third inverter, and the input of the third inverter is used for receiving the state signal of the on/off state of the lower tube; the source electrode of the second MOS tube is connected with the drain electrode of the third MOS tube, and the source electrode of the third MOS tube is grounded; the grid electrode of the third MOS tube is connected with the grid electrode of the fourth MOS tube, the source electrode of the fourth MOS tube is grounded, the drain electrode of the fourth MOS tube is connected with a voltage source, and the drain electrode of the fourth MOS tube is in short circuit with the grid electrode;
the input end of the first inverter is connected with the source electrode of the first MOS tube, and the output end of the first inverter is connected with the input end of the second inverter; the output end of the second inverter is connected with the input ends of the first trigger and the second trigger, and the output end of the first trigger outputs a first judgment state signal; the output end of the second trigger outputs a second judging state signal;
the output signal of the third inverter is used as the clock signal of the first trigger, and the output signal of the third inverter is delayed by the delay unit and then used as the clock signal of the second trigger.
3. The self-calibrating zero-crossing current detection circuit of a switching power supply chip as claimed in claim 1, wherein said zero-crossing comparison module comprises:
the device comprises a comparator, a trigger, a NAND gate, an inverter, a first resistor, a second resistor and a trimming resistor unit;
one end of the trimming resistor unit is connected to the power ground, the other end of the trimming resistor unit is connected to one end of the second resistor, and the other end of the second resistor is connected to the negative electrode input end of the comparator and the power supply;
one end of the first resistor is connected with the SW node, and the other end of the first resistor is connected with the positive input end of the comparator and the power supply;
the trimming resistor unit receives the trimming signal of the zero-crossing detection calibration module, and trims the offset voltage of the comparator by adjusting the resistance value of the trimming resistor unit;
the input end of the trigger is connected with a power supply, and the state signal of the on/off state of the down tube is used as a clock signal of the trigger;
the output end of the comparator and the output end of the trigger are used as two output ends of the NAND gate, the output end of the NAND gate is connected with the input end of the inverter, and the output end of the inverter outputs the zero-crossing current detection signal.
4. The self-calibrating zero-crossing current detection circuit of a switching power supply chip as claimed in claim 1, wherein said zero-crossing comparison module comprises:
the comparator, the trimming resistor unit and the AND gate;
the trimming resistor unit comprises a plurality of trimming resistors which are connected in series, one end of the trimming resistor unit is connected with the power ground, and the other end of the trimming resistor unit is connected with the negative electrode input end of the comparator;
the two input ends of the AND gate are respectively used for inputting the output signal of the comparator and the on/off state signal of the lower pipe;
the AND gate outputs the zero-crossing current detection signal.
5. A switching power supply chip comprising the self-calibrating zero-crossing current detection circuit of any one of claims 1-4.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204423219U (en) * | 2015-01-19 | 2015-06-24 | 浙江商业职业技术学院 | Zero passage detection imbalance correcting device |
| CN208158409U (en) * | 2018-04-25 | 2018-11-27 | 东莞市长工微电子有限公司 | A kind of self calibration zero cross detection circuit applied to BUCK Switching Power Supply |
| CN111786661A (en) * | 2020-09-04 | 2020-10-16 | 苏州赛芯电子科技有限公司 | Self-calibration zero-crossing comparator and direct-current conversion circuit |
| CN113037063A (en) * | 2021-05-25 | 2021-06-25 | 珠海市杰理科技股份有限公司 | Zero-crossing self-calibration circuit, DC/DC converter and power management chip |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204423219U (en) * | 2015-01-19 | 2015-06-24 | 浙江商业职业技术学院 | Zero passage detection imbalance correcting device |
| CN208158409U (en) * | 2018-04-25 | 2018-11-27 | 东莞市长工微电子有限公司 | A kind of self calibration zero cross detection circuit applied to BUCK Switching Power Supply |
| CN111786661A (en) * | 2020-09-04 | 2020-10-16 | 苏州赛芯电子科技有限公司 | Self-calibration zero-crossing comparator and direct-current conversion circuit |
| CN113037063A (en) * | 2021-05-25 | 2021-06-25 | 珠海市杰理科技股份有限公司 | Zero-crossing self-calibration circuit, DC/DC converter and power management chip |
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