Energy storage type power supply control system and control method

Abstract

The invention discloses a power supply control system with an energy storage capacitor. The power supply control system comprises a DC / DC converter and a bidirectional switch circuit. The DC / DC converter receives a power supply voltage and provides a system voltage to a post-stage circuit. The first end of the bidirectional switching circuit is coupled to the energy storage capacitor, and the second end of the bidirectional switching circuit is coupled to the output end of the DC / DC converter. When the system voltage is lower than a system low-voltage threshold value and the voltage of the energy storage capacitor is higher than an energy storage foot-voltage threshold value, the bidirectional switching circuit transmits power in the energy storage capacitor to the output end of the DC / DC converter. When the system voltage is higher than a system foot voltage threshold value and the voltage of the energy storage capacitor is lower than an energy storage low voltage threshold value, the bidirectional switching circuit transmits the power of the output end of the DC / DC converter to the energy storage capacitor. According to the power supply control system provided by the invention, the energy storage capacitor is adopted to store energy, and when the module generates transient large current, the energy storage capacitor provides energy for the load, so that the problem that the system voltage is pulled and pressed is avoided.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a power supply control system and a corresponding control method. Background Art

[0002] Current mobile devices, such as cell phones and tablets, are mostly battery-powered. Because each module in a mobile device has different voltage and current requirements, different voltage conversion circuits are required to convert the battery voltage into the required voltage value before supplying it to each module. Figure 1 FIG. 1 shows a block diagram of a two-stage power supply system 100 in a mobile device. Figure 1 As shown, in the two-stage power supply system 100, the first-stage DC / DC (DC to DC) converter 101 converts the battery voltage Vbatt into the system voltage Vsys, and the second-stage DC / DC converters 102 and LDO 103 further convert the system voltage Vsys into the voltages V1-V required by each module. n .

[0003] In some scenarios, some modules generate transient high currents. For example, when a mobile phone call is connected, the power of the communication module suddenly increases, generating a transient high current. This transient high current pulls down the battery voltage Vbatt and the system voltage Vsys provided by the first-stage DC / DC converter 101, resulting in insufficient system power supply and causing other modules to fail.

[0004] To address the issues caused by transient high currents in some modules, the first-stage DC / DC converter typically uses multiple DC / DC converters in parallel or a multi-phase DC / DC converter. However, both these approaches are costly and complex to control, and the power control system occupies a large area within the mobile device. Summary of the Invention

[0005] This application provides a power supply control system that uses energy storage capacitors to store energy. When a module generates a transient high current, the energy storage capacitors provide energy to the load, thereby avoiding the problem of system voltage being pulled or compressed. This system does not require the use of multiple DC / DC converters in parallel or multi-phase DC / DC converters, and is low in cost, simple and reliable in control, and occupies a small area.

[0006] According to one embodiment of the present invention, a power supply control system with an energy storage capacitor is provided, comprising: a DC / DC (direct current to direct current) converter having an input and an output, the input receiving a power supply voltage and the output providing a system voltage; and a bidirectional switch circuit having a first end and a second end, the first end coupled to the energy storage capacitor and the second end coupled to the output of the DC / DC converter; wherein, when the system voltage is lower than a system low-voltage threshold and the voltage of the energy storage capacitor is higher than an energy storage sufficient voltage threshold, the bidirectional switch circuit transfers the power in the energy storage capacitor to the output of the DC / DC converter; and when the system voltage is higher than the system sufficient voltage threshold and the voltage of the energy storage capacitor is lower than the energy storage low-voltage threshold, the bidirectional switch circuit transfers the power from the output of the DC / DC converter to the energy storage capacitor.

[0007] According to one embodiment of the present invention, a control method for a power supply control system is provided, wherein the power supply control system includes an energy storage capacitor, a bidirectional switching circuit, and a DC / DC converter. The control method includes: detecting the energy storage capacitor voltage and the system voltage provided by the DC / DC converter, providing an energy storage capacitor voltage feedback signal representing the energy storage capacitor voltage and a system voltage feedback signal representing the system voltage; when the energy storage capacitor voltage feedback signal is less than the energy storage capacitor low voltage reference and the system voltage feedback signal is greater than the system full voltage reference, controlling the bidirectional switching circuit to charge the energy storage capacitor; and when the energy storage capacitor voltage feedback signal is greater than the energy storage capacitor full voltage reference and the system voltage feedback signal is less than the system low voltage reference, controlling the bidirectional switching circuit to discharge the energy storage capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above and other objects, features and advantages of the present application will become more apparent through the following description of the embodiments of the present application with reference to the accompanying drawings:

[0009] Figure 1 A structural block diagram of a two-stage power supply system 100 in an existing mobile device is shown;

[0010] Figure 2 1 shows a schematic diagram of the module structure of a power supply control system 200 according to an embodiment of the present invention;

[0011] Figure 3 FIG2 shows a circuit structure diagram of a bidirectional switch circuit 300 according to an embodiment of the present application;

[0012] Figure 4 1 is a schematic diagram showing waveforms of some signals in a bidirectional switch circuit 300 according to an embodiment of the present application;

[0013] Figure 5 FIG2 shows a circuit structure diagram of a bidirectional switch circuit 500 according to an embodiment of the present application;

[0014] Figure 6 FIG. 6 is a flow chart of a control method 600 of a power supply control system according to an embodiment of the present application. DETAILED DESCRIPTION

[0015] Specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the present invention. In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details are not necessarily required to practice the present invention. In other instances, well-known circuits, materials, or methods are not described in detail to avoid obscuring the present invention.

[0016] The terms "first," "second," and so forth in the following description are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified with "first," "second," and so forth may explicitly or implicitly include one or more of such features. Throughout the description of this application, unless otherwise specified, "plurality" means two or more.

[0017] In addition, in this application, directional terms such as "upper" and "lower" may be defined including but not limited to the orientation relative to the schematic placement of the components in the drawings. It should be understood that these directional terms may be relative concepts. They are used for relative descriptions and clarifications, and they may change accordingly according to changes in the orientation of the components in the drawings.

[0018] In this application, unless otherwise specified or limited, the term "connection" should be understood broadly. For example, "connection" can mean fixed connection, detachable connection, or integration; it can mean direct connection or indirect connection through an intermediate medium. In addition, the term "coupling" can refer to the method of electrical connection for signal transmission. "Coupling" can mean direct electrical connection or indirect electrical connection through an intermediate medium.

[0019] Figure 2 FIG. 2 shows a schematic diagram of a module structure of a power supply control system 200 according to an embodiment of the present invention. Figure 2 As shown, the power control system 200 includes a DC / DC converter 202 and a bidirectional switch circuit 203. The DC / DC converter 202 has an input terminal IN and an output terminal OUT. The input terminal IN is connected to the battery 201 and receives the battery voltage Vbatt, that is, the power supply voltage. The output terminal OUT provides the system voltage Vsys to the subsequent circuit 204. The subsequent circuit 204 may include various power modules in the device, and may also include a subsequent voltage conversion circuit, such as Figure 1The second-stage DC / DC converter 102 and LDO 103 are shown. The bidirectional switch circuit 203 has a first terminal B1 and a second terminal B2. The first terminal B1 is connected to the energy storage capacitor C1, and the second terminal B2 is connected to the output terminal OUT of the DC / DC converter 202. Based on the voltage Vc1 on the energy storage capacitor C1 and the system voltage Vsys at the output terminal OUT of the DC / DC converter 202, the bidirectional switch circuit 203 charges or discharges the energy storage capacitor C1.

[0020] In some embodiments, when the load of the battery 201 is in a stable working state and the load power consumption is in a roughly stable state, the battery 201 provides the system voltage Vsys to the subsequent circuit 204 through the DC / DC converter 202, thereby providing power to the subsequent load. At the same time, the output of the DC / DC converter 202 further charges the energy storage capacitor C1 through the bidirectional switch circuit 203. The current path is as follows: Figure 2 As shown by the arrow direction of the charging current Icharge. When the energy storage capacitor C1 is charged, the battery 201 not only supplies power to the subsequent circuit 204 through the DC / DC converter 202, but also charges the energy storage capacitor C1 through the DC / DC converter 202 and the bidirectional switch circuit 203. When the charge of the energy storage capacitor C1 reaches a certain amount, or the voltage Vc1 of the energy storage capacitor C1 reaches a certain voltage, the bidirectional switch circuit 203 stops working. At this time, the battery 201 continues to provide the system voltage Vsys and power to the subsequent circuit through the DC / DC converter 202. When the subsequent load module generates a transient large current, the load of the DC / DC converter 202 suddenly increases, and its output current becomes larger instantly, causing the system voltage Vsys to be pulled down. When the system voltage Vsys is lower than a certain value, the bidirectional switch circuit 203 starts working and provides the energy of the energy storage capacitor C1 to the subsequent circuit 204. In other words, the bidirectional switch circuit 203 discharges the energy storage capacitor C1, and the discharge path is as follows Figure 2 As shown by the arrow direction of the discharge current Idischarge, the energy storage capacitor C1 supplies power to the subsequent circuit 204 through the bidirectional switch circuit 203. In this state, the energy storage capacitor C1 and the battery 201 jointly supply power to the subsequent circuit 204 to cope with the transient high current of the subsequent circuit 204, preventing the system voltage Vsys from being pulled down to a level that affects the operation of the subsequent circuits and modules, thereby avoiding the problem of transient high currents in some modules causing failure of other modules.

[0021] The DC / DC converter 202 may be any suitable voltage conversion circuit that can convert a DC voltage into another target DC voltage. Figure 2 In the embodiment, since the energy storage capacitor C1 is used to cope with the transient high current working condition, the current capability requirement of the DC / DC converter 202 is not high, so the selection range thereof can be further expanded.

[0022] exist Figure 2 In this embodiment, the battery is used as a power source to power the subsequent circuit and charge the energy storage capacitor C1. In other embodiments, other power sources can also be used to provide power voltage to the DC / DC circuit 202.

[0023] Figure 3 FIG. 1 shows a schematic diagram of a circuit structure of a bidirectional switch circuit 300 according to an embodiment of the present application. Figure 3 As shown, the bidirectional switch circuit 300 includes a power circuit 31 , a first control circuit 302 and a second control circuit 303 .

[0024] exist Figure 3 In one embodiment, the power circuit 31 includes a first switch M1, a second switch M2, and an inductor L1. The first switch M1 and the second switch M2 each have a first terminal, a second terminal, and a control terminal. The first terminal of the first switch M1 is coupled to the first terminal B1 of the bidirectional switch circuit 300, the second terminal is coupled to the switch terminal BSW, and the control terminal receives a first control signal G1. The first terminal of the second switch M2 is coupled to the switch terminal BSW, the second terminal is coupled to the ground terminal GND, and the control terminal receives a second control signal G2. The inductor L1 has a first terminal and a second terminal, the first terminal of the inductor L1 being coupled to the switch terminal BSW and the second terminal being coupled to the second terminal B2 of the bidirectional switch circuit 300. The bidirectional switch circuit 300 further includes a capacitor C2 coupled between the first terminal B1 and the ground terminal GND, and a capacitor C3 coupled between the second terminal B2 and the ground terminal GND.

[0025] In one embodiment, when the energy storage capacitor C1 is charged, the first control circuit 32 controls the power circuit 31 to operate in a boost mode, with current flowing from the second terminal B2 to the first terminal B1. When the energy storage capacitor C1 is discharged, the second control circuit 33 controls the power circuit 31 to operate in a buck mode, with current flowing from the first terminal B1 to the second terminal B2 of the power circuit 31. When the first control circuit 32 is operating, the second control circuit 33 is deactivated, and vice versa.

[0026] exist Figure 3 In this embodiment, the first control circuit 32 has a first input terminal coupled to the first terminal B1 of the bidirectional switch circuit 300 to receive the voltage Vc1 of the energy storage capacitor C1, and a second input terminal coupled to the second terminal B2 of the bidirectional switch circuit 300 to receive the system voltage Vsys. Based on the voltage Vc1 of the energy storage capacitor C1 and the system voltage Vsys, the first control circuit 32 outputs a second control signal G2 at a first output terminal to control the on / off switching of the second switch M2, and outputs a first control signal G1 at a second output terminal to control the on / off switching of the first switch M1.

[0027] exist Figure 3 In the embodiment, the first control circuit 32 includes a charging determination circuit 321 and a charging control circuit 322 .

[0028] The charging judgment circuit 321 includes a first charging judgment comparison circuit 301, a second charging judgment comparison circuit 302, and an AND gate circuit 303. The first charging judgment comparison circuit 301 has a first input terminal receiving the energy storage capacitor low voltage reference Vcref1, a second input terminal receiving the energy storage capacitor voltage feedback signal Vcfb, and an output terminal providing a first charging judgment signal Sd. The second charging judgment comparison circuit 302 has a first input terminal receiving the system voltage feedback signal Vofb, a second input terminal receiving the system full voltage reference Voref1, and an output terminal providing a second charging judgment signal S c The AND gate circuit 303 has a first input terminal for receiving the first charge determination signal Sd and a second input terminal for receiving the second charge determination signal S c , with an output terminal providing a charging enable signal EN c .

[0029] The charging control circuit 322 includes a fixed time circuit 304 and an RS trigger circuit 305. When the on-time of the second switch M2 reaches the set time, the fixed time circuit 304 outputs a charging shutdown signal ONd1. The RS trigger circuit 305 has a set terminal "S" to receive the charging enable signal ENc, a reset terminal "R" to receive the charging shutdown signal ONd1, a first output terminal "Q" to output the second control signal G2 to control the on-off of the second switch M2, and a second output terminal "QB" to output the first control signal G1 to control the on-off of the first switch M1. The fixed time circuit 304 can detect the charging enable signal ENc by c , the second control signal G2 or other signals related to the conduction action of the second switch M2 are used to determine the starting point of the conduction duration of the second switch M2, and when the conduction duration of the second switch M2 reaches a preset duration, the RS trigger circuit 305 is reset, so that the RS trigger circuit 305 outputs the second control signal G2 to control the second switch M2 to be turned off.

[0030] When the first charging judgment signal Sd indicates that the energy storage capacitor voltage feedback signal Vcfb is less than the energy storage capacitor low voltage reference Vcref1, and the second charging judgment signal S c When the system voltage feedback signal Vofb is greater than the system full voltage reference Voref1 , the first control circuit 32 controls the power circuit 31 to operate in the boost mode, the first switch M1 and the second switch M2 are alternately turned on and off, and the energy storage capacitor C1 is charged.

[0031] exist Figure 3In this embodiment, the second control circuit 33 has a first input terminal coupled to the first terminal B1 of the bidirectional switch circuit 300 to receive the voltage Vc1 of the energy storage capacitor C1, and a second input terminal coupled to the second terminal B2 of the bidirectional switch circuit 300 to receive the system voltage Vsys. Based on the voltage Vc1 of the energy storage capacitor C1 and the system voltage Vsys, the second control circuit 33 outputs a first control signal G1 at a first output terminal to control the on / off switching of the first switch M1, and outputs a second control signal G2 at a second output terminal to control the on / off switching of the second switch M2.

[0032] exist Figure 3 In the embodiment, the second control circuit 33 includes a discharge determination circuit 331 and a discharge control circuit 332 .

[0033] The discharge determination circuit 331 includes a first discharge determination comparison circuit 306, a second discharge determination comparison circuit 307, and an AND gate circuit 308. The first discharge determination comparison circuit 306 has a first input terminal for receiving the energy storage capacitor voltage feedback signal Vcfb, a second input terminal for receiving the energy storage capacitor full voltage reference Vcref2, and an output terminal for providing a first discharge determination signal Sb. The second discharge determination comparison circuit 307 has a first input terminal for receiving the system low voltage reference Voref2, a second input terminal for receiving the system voltage feedback signal Vofb, and an output terminal for providing a second discharge determination signal Sa. The AND gate circuit 308 has a first input terminal for receiving the first discharge determination signal Sb, a second input terminal for receiving the second discharge determination signal Sa, and an output terminal for providing a discharge enable signal ENd.

[0034] The discharge control circuit 332 includes a fixed-duration circuit 309 and an RS trigger circuit 310. When the on-duration of the first switch M1 reaches a set duration, the fixed-duration circuit 309 outputs a discharge-off signal ONd2. The RS trigger circuit 310 has a set terminal "S" for receiving the discharge enable signal ENd, a reset terminal "R" for receiving the discharge-off signal ONd2, a first output terminal "Q" for outputting a first control signal G1 to control the on / off of the first switch M1, and a second output terminal "QB" for outputting a second control signal G2 to control the on / off of the second switch M2. The fixed-duration circuit 309 can determine the starting point of the on-duration of the first switch M1 by detecting the discharge enable signal ENd, the first control signal G1, or other signals related to the on-duration of the first switch M1. When the on-duration of the first switch M1 reaches the preset duration, the RS trigger circuit 310 is reset, causing the RS trigger circuit 310 to output the first control signal G1 to turn off the first switch M1.

[0035] When the first discharge judgment signal Sb indicates that the energy storage capacitor voltage feedback signal Vcfb is greater than the energy storage capacitor full voltage reference Vcref2, and the second discharge judgment signal Sa indicates that the system voltage feedback signal Vofb is less than the system low voltage reference Voref2, the second control circuit 33 controls the power circuit 31 to operate in the buck mode, the first switch M1 and the second switch M2 are alternately turned on and off, and the energy storage capacitor C1 is discharged.

[0036] Figure 4 FIG2 shows a waveform diagram of some signals in the bidirectional switch circuit 300 according to an embodiment of the present application. Figure 3 and Figure 4 To further illustrate the working principle of the bidirectional switch circuit 300.

[0037] like Figure 4 As shown, at time t1, the load current suddenly increases, causing the system voltage Vsys to drop sharply, causing the system voltage feedback signal Vofb to drop below the system low-voltage reference Voref2. At this time, the energy storage capacitor voltage feedback signal Vcfb is greater than the energy storage capacitor full-voltage reference Vcref2. The first discharge determination signal Sb and the second discharge determination signal Sa are both high. The discharge enable signal ENd output by the AND gate circuit 308 jumps from a low level to a high level, and the trigger circuit 310 is set. The first control signal G1 jumps to a high level, turning on the first switch M1. The second control signal G2 is low, turning off the second switch M2. When the on-time of the first switch M1 reaches a preset time, the discharge off signal ONd2 output by the fixed time circuit 309 resets the RS trigger circuit 310. The first control signal G1 jumps to a low level, turning off the first switch M1. The second control signal G2 jumps to a high level, turning on the second switch M2. The first switch M1 and the second switch M2 are alternately turned on, so that the power circuit 31 operates in the buck mode. Current flows from the first terminal B1 to the second terminal B2 of the bidirectional switch circuit 300, and the energy storage capacitor C1 is discharged to compensate for the transient large current of the load and prevent the system voltage Vsys from dropping.

[0038] At time t2, the transient high current ends. Because the energy storage capacitor voltage feedback signal Vcfb drops below the energy storage capacitor low voltage reference Vcref1, and the system voltage feedback signal Vofb has recovered to above the system full voltage reference Voref1, the first charging judgment signal Sd and the second charging judgment signal S c Both are high level, and the charging enable signal EN output by the AND gate circuit 303 cThe trigger circuit 305 is set when the second control signal G2 jumps to a high level, turning on the second switch M2. The first control signal G1 is at a low level, turning off the first switch M1. When the on-time of the second switch M2 reaches a preset time, the charging shutdown signal ONd1 output by the fixed-time circuit 304 resets the RS trigger circuit 305. The second control signal G2 jumps to a low level, turning off the second switch M2. The first control signal G1 jumps to a high level, turning on the first switch M1. The first and second switches M1 and M2 are alternately turned on, causing the power circuit 31 to operate in boost mode. Current flows from the second terminal B2 of the bidirectional switch circuit 300 to the first terminal B1, charging the energy storage capacitor C1 and increasing the voltage Vc1 of the energy storage capacitor.

[0039] In one embodiment, the system full voltage reference Voref1 is greater than the system low voltage reference Voref2, and the energy storage capacitor full voltage reference Vcref2 is greater than the energy storage capacitor low voltage reference Vcref1. The system full voltage reference Voref1, the system low voltage reference Voref2, the energy storage capacitor full voltage reference Vcref2, and the energy storage capacitor low voltage reference Vcref1 can be set according to specific application requirements.

[0040] exist Figure 3 In this embodiment, the charging control circuit 322 and the discharging control circuit 332 include a constant on-time control circuit, that is, the on-time of the main switch in the power circuit is fixed. In other embodiments, the charging control circuit 322 and the discharging control circuit 332 may also include other types of control circuits, such as a fixed off-time control circuit, a voltage-type control circuit, a current-type control circuit, etc.

[0041] Figure 5 FIG. 5 shows a schematic diagram of a circuit structure of a bidirectional switch circuit 500 according to an embodiment of the present application. Figure 5 As shown, the bidirectional switch circuit 500 includes a power circuit 31, a first control circuit 502 and a second control circuit 503. The first control circuit 502 and the second control circuit 503 include peak current control circuits.

[0042] Figure 5 The structure and working principle of the bidirectional switch circuit 500 of the embodiment are similar to those of the bidirectional switch circuit 300. The difference from the bidirectional switch circuit 300 is that Figure 5 In an embodiment, the charge control circuit 522 and the discharge control circuit 532 include peak current control circuits.

[0043] exist Figure 5 In the embodiment, the first control circuit 52 includes a charging determination circuit 321 and a charging control circuit 522 .

[0044] The structure and working principle of the charging determination circuit 321 are as described above and will not be repeated here.

[0045] The charging control circuit 522 includes an AND gate circuit 501, a first error amplifier circuit 502, a first feedback comparison circuit 503 and an RS trigger circuit 504. The AND gate circuit 501 has a first input terminal receiving a charging enable signal EN. c , having a second input terminal for receiving the first clock signal CLK1, and an output terminal for outputting the first set signal St1. The first error amplifier circuit 502 has a first input terminal for receiving the energy storage capacitor voltage feedback signal Vcfb, a second input terminal for receiving the energy storage capacitor voltage reference Vref1, and an output terminal for outputting the energy storage capacitor voltage adjustment signal Vcomp1. The first feedback comparator circuit 503 has a first input terminal for receiving the charging current detection signal I1, a second input terminal for receiving the energy storage capacitor voltage adjustment signal Vcomp1, and an output terminal for providing the peak current shutdown signal Pd1. The charging current detection signal I1 represents the current flowing through the inductor L1 when the power circuit 31 operates in the boost mode. The RS trigger circuit 504 has a set terminal "S" for receiving the first set signal St1, a reset terminal "R" for receiving the peak current shutdown signal Pd1, a first output terminal "Q" for outputting the second control signal G2 to control the on / off of the second switch M2, and a second output terminal "QB" for outputting the first control signal G1 to control the on / off of the first switch M1.

[0046] When the first charging judgment signal Sd indicates that the energy storage capacitor voltage feedback signal Vcfb is less than the energy storage capacitor low voltage reference Vcref1, and the second charging judgment signal S c When the system voltage feedback signal Vofb is greater than the system voltage reference Voref1, the first control circuit 52 controls the power circuit 31 to work in the boost mode, the first switch M1 and the second switch M2 are alternately turned on and off, and the energy storage capacitor C1 is charged. c When AND gate circuit 501 is turned on, the first clock signal CLK1 is used as the first set signal St1 to set RS flip-flop 504. When a pulse of the first clock signal CLK1 arrives, the second control signal G2 jumps to a high level, turning on the second switch M2. The first control signal G1 is at a low level, and the first switch M1 remains off. When the second switch M2 is turned on, inductor L1 is charged, and the inductor current increases. When the charging current detection signal I1 representing the inductor current rises to the energy storage capacitor voltage regulation signal Vcomp1, the first feedback comparator circuit 503 outputs a peak current shutdown signal Pd1 to reset RS flip-flop 504. The second control signal G2 jumps to a low level, and the first control signal G1 jumps to a high level, turning off the second switch M2 and turning on the first switch M1. The first and second switches M1 and M2 alternately turn on and off, causing the power circuit 31 to operate in boost mode, charging the energy storage capacitor C1.

[0047] exist Figure 5 In this embodiment, the second control circuit 53 has a first input terminal coupled to the first terminal B1 of the bidirectional switch circuit 500 to receive the voltage Vc1 of the energy storage capacitor C1, and a second input terminal coupled to the second terminal B2 of the bidirectional switch circuit 500 to receive the system voltage Vsys. Based on the voltage Vc1 of the energy storage capacitor C1 and the system voltage Vsys, the second control circuit 53 outputs a first control signal G1 at a first output terminal to control the on / off switching of the first switch M1, and outputs a second control signal G2 at a second output terminal to control the on / off switching of the second switch M2.

[0048] exist Figure 5 In the embodiment, the second control circuit 53 includes a discharge determination circuit 331 and a discharge control circuit 532 .

[0049] The structure and working principle of the discharge determination circuit 331 are as described above and will not be repeated here.

[0050] The discharge control circuit 532 includes an AND gate circuit 505, a second error amplifier circuit 506, a second feedback comparator circuit 507, and an RS trigger circuit 508. The AND gate circuit 505 has a first input terminal for receiving a discharge enable signal ENd, a second input terminal for receiving a second clock signal CLK2, and an output terminal for outputting a second set signal St2. The second error amplifier circuit 506 has a first input terminal for receiving a storage capacitor voltage feedback signal Vofb, a second input terminal for receiving a system voltage reference Vref2, and an output terminal for outputting a system voltage regulation signal Vcomp1. The second feedback comparator circuit 507 has a first input terminal for receiving a discharge current detection signal I2, a second input terminal for receiving the system voltage regulation signal Vcomp2, and an output terminal for providing a peak current shutdown signal Pd2. The discharge current detection signal I1 represents the current flowing through the inductor L1 when the power circuit 31 is operating in buck mode. The RS trigger circuit 508 has a set terminal "S" to receive the second set signal St2, a reset terminal "R" to receive the peak current shutdown signal Pd2, a first output terminal "Q" to output the first control signal G1 to control the on and off of the first switch M1, and a second output terminal "QB" to output the second control signal G2 to control the on and off of the second switch M2.

[0051] When the first discharge determination signal Sb indicates that the energy storage capacitor voltage feedback signal Vcfb is greater than the energy storage capacitor full voltage reference Vcref2, and the second discharge determination signal Sa indicates that the system voltage feedback signal Vofb is less than the system low voltage reference Voref2, the second control circuit 53 controls the power circuit 31 to operate in buck mode, with the first switch M1 and the second switch M2 alternately turned on and off, discharging the energy storage capacitor C1. In this mode, the discharge enable signal ENd activates the AND gate 505, and the second clock signal CLK2 is used as the second set signal St2 to set the RS flip-flop 508. When the second clock signal CLK2 pulse arrives, the first control signal G1 jumps to a high level, turning on the first switch M1. The second control signal G2 is at a low level, and the second switch M2 remains off. When the first switch M1 is turned on, the inductor L1 is charged, and the inductor current increases. When the discharge current detection signal I2, representing the inductor current, rises above the system voltage regulation signal Vcomp2, the second feedback comparator circuit 507 outputs a peak current shutdown signal Pd2, which resets the RS flip-flop 508. The first control signal G1 transitions to a low level, the second control signal G2 transitions to a high level, the first switch M1 turns off, and the second switch M2 turns on. The first and second switches M1 and M2 alternately turn on and off, causing the power circuit 31 to operate in buck mode, discharging the energy storage capacitor C1.

[0052] This application Figure 3 The embodiment shows an embodiment in which the charging control circuit 322 in the first control circuit 32 and the discharging control circuit 332 in the second control circuit 33 include a fixed-time conduction control circuit. Figure 5 The embodiment shows an embodiment in which the charging control circuit 522 in the first control circuit 52 and the discharging control circuit 532 in the second control circuit 53 include a peak current control circuit. It should be understood that in other embodiments, the discharging control circuit and the charging control circuit may use different control circuits. For example, the charging control circuit may use a fixed-duration conduction control circuit and the discharging control circuit may use a peak current control circuit, or vice versa. Other types of control circuits may also be used, and the present invention is not limited thereto.

[0053] Figure 6 FIG. 6 is a flow chart showing a control method 600 of a power supply control system according to an embodiment of the present application. The power supply control system includes: Figure 2 The power control system 200 shown in the embodiment. Figure 6As shown, the control method 600 includes: step 601, detecting the energy storage capacitor voltage and the system voltage provided by the DC / DC converter, and providing an energy storage capacitor voltage feedback signal representing the energy storage capacitor voltage and a system voltage feedback signal representing the system voltage; step 602, when the energy storage capacitor voltage feedback signal is less than the energy storage capacitor low voltage reference, and the system voltage feedback signal is greater than the system full voltage reference, controlling the bidirectional switch circuit to charge the energy storage capacitor; and step 603, when the energy storage capacitor voltage feedback signal is greater than the energy storage capacitor full voltage reference, and the system voltage feedback signal is less than the system low voltage reference, controlling the bidirectional switch circuit to discharge the energy storage capacitor.

[0054] In one embodiment, the voltage of the energy storage capacitor is greater than the system voltage output by the DC / DC converter. When the bidirectional switch circuit charges the energy storage capacitor, the bidirectional switch circuit operates in a boost mode. When the bidirectional switch circuit discharges the energy storage capacitor, the bidirectional switch circuit operates in a buck mode.

[0055] It should be understood that the logic circuits and the positive and negative input terminals of the corresponding comparators and error amplifiers in the embodiments of the present application are for illustrative purposes only. When the polarity of the signal is opposite, the polarity of the corresponding logic circuits and the input terminals may change.

[0056] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0057] The above description is only a preferred embodiment of the present application and does not constitute any formal limitation to the present application. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present application without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of protection of the technical solution of the present application.

Claims

1. A power supply control system with an energy storage capacitor, comprising: A DC / DC (direct current to direct current) converter having an input terminal and an output terminal, wherein the input terminal receives a power supply voltage and the output terminal provides a system voltage; as well as a bidirectional switch circuit having a first terminal and a second terminal, wherein the first terminal is coupled to the energy storage capacitor, and the second terminal is coupled to the output terminal of the DC / DC converter; in, When the system voltage is lower than the system low-voltage threshold and the voltage of the energy storage capacitor is higher than the energy storage sufficient voltage threshold, the bidirectional switch circuit transfers the power in the energy storage capacitor to the output end of the DC / DC converter; When the system voltage is higher than the system full voltage threshold and the voltage of the energy storage capacitor is lower than the energy storage low voltage threshold, the bidirectional switch circuit transfers the power at the output end of the DC / DC converter to the energy storage capacitor.

2. The power control system according to claim 1, wherein the bidirectional switch circuit comprises: A power circuit comprising a first switch, a second switch, and an inductor, wherein the first switch is coupled between a switch terminal and a first terminal of the bidirectional switch circuit, the second switch is coupled between the switch terminal and a ground terminal, and the inductor is coupled between the switch terminal and a second terminal of the bidirectional switch circuit; a first control circuit having a first input terminal for receiving a storage capacitor voltage feedback signal representing a storage capacitor voltage, a second output terminal for receiving a system voltage feedback signal representing a system voltage, the first output terminal for outputting a first control signal for controlling the on / off of the first switch, and a second output terminal for outputting a second control signal for controlling the on / off of the second switch; as well as The second control circuit has a first input end for receiving a storage capacitor voltage feedback signal representing the energy storage capacitor voltage, a second output end for receiving a system voltage feedback signal representing the system voltage, a first output end for outputting a first control signal to control the on and off of the first switch, and a second output end for outputting a second control signal to control the on and off of the second switch.

3. The power control system according to claim 2, wherein the first control circuit comprises: a charging judgment circuit having a first input terminal receiving a storage capacitor voltage feedback signal representing the energy storage capacitor voltage, a second input terminal receiving a system voltage feedback signal representing the system voltage, and an output terminal providing a charging enable signal; as well as a charging control circuit having a first input terminal for receiving a charging enable signal, a first output terminal for providing a second control signal, and a second output terminal for providing the first control signal; Among them, when the energy storage capacitor voltage feedback signal is less than the energy storage capacitor low voltage reference and the system voltage feedback signal is greater than the system full voltage reference, the charging enable signal enables the charging control circuit to output the second control signal and the first control signal to control the on and off of the second switch and the first switch respectively.

4. The power control system according to claim 3, wherein the charging control circuit comprises: A fixed time circuit outputs a charging shutdown signal when the second switch is on for a set time. as well as The RS trigger circuit has a set terminal for receiving a charging enable signal, a reset terminal for receiving a charging shutdown signal, a first output terminal for outputting a second control signal for controlling the on and off of the second switch, and a second output terminal for outputting a first control signal for controlling the on and off of the first switch.

5. The power control system according to claim 3, wherein the charging control circuit comprises: An AND gate circuit having a first input terminal for receiving a charge enable signal, a second input terminal for receiving a first clock signal, and an output terminal for outputting a first set signal; A first error amplifier circuit has a first input terminal for receiving a voltage feedback signal of an energy storage capacitor, a second input terminal for receiving a voltage reference of an energy storage capacitor, and an output terminal for outputting a voltage adjustment signal of an energy storage capacitor; A first feedback comparison circuit has a first input terminal for receiving a charging current detection signal, a second input terminal for receiving a storage capacitor voltage adjustment signal, and an output terminal for providing a peak current shutdown signal; as well as The RS trigger circuit has a set end for receiving a first set signal, a reset end for receiving a peak current shutdown signal, a first output end for outputting a second control signal for controlling the on and off of the second switch, and a second output end for outputting a first control signal for controlling the on and off of the first switch.

6. The power control system according to claim 2, wherein the second control circuit comprises: a discharge judgment circuit having a first input terminal receiving a storage capacitor voltage feedback signal representing the energy storage capacitor voltage, a second input terminal receiving a system voltage feedback signal representing the system voltage, and an output terminal providing a discharge enable signal; as well as a discharge control circuit having a first input terminal for receiving a discharge enable signal, a first output terminal for providing a second control signal, and a second output terminal for providing the first control signal; When the energy storage capacitor voltage feedback signal is greater than the energy storage capacitor full voltage reference and the system voltage feedback signal is less than the system low voltage reference, the discharge enable signal enables the first discharge control circuit to output the first control signal and the second control signal to control the on and off of the first switch and the second switch respectively.

7. The power control system according to claim 6, wherein the discharge control circuit comprises: A fixed-time circuit outputs a discharge shutoff signal when the first switch is on for a set time. as well as The RS trigger circuit has a set terminal for receiving a discharge enable signal, a reset terminal for receiving a discharge shutdown signal, a first output terminal for outputting a first control signal for controlling the on and off of the first switch, and a second output terminal for outputting a second control signal for controlling the on and off of the second switch.

8. The power control system according to claim 6, wherein the discharge control circuit comprises: An AND gate circuit having a first input terminal for receiving a discharge enable signal, a second input terminal for receiving a second clock signal, and an output terminal for outputting a second set signal; a second error amplifier having a first input terminal for receiving a system voltage feedback signal, a second input terminal for receiving a system voltage reference, and an output terminal for outputting a system voltage regulation signal; a feedback comparator having a first input terminal for receiving a charging current detection signal, a second input terminal for receiving a system voltage regulation signal, and an output terminal for providing a peak current shutdown signal; as well as The RS trigger circuit has a set terminal for receiving a first set signal, a reset terminal for receiving a peak current shutdown signal, a first output terminal for outputting a first control signal for controlling the on and off of the first switch, and a second output terminal for outputting a second control signal for controlling the on and off of the second switch.

9. A control method for a power supply control system, the power supply control system comprising an energy storage capacitor, a bidirectional switch circuit, and a DC / DC converter, the control method comprising: detecting the energy storage capacitor voltage and the system voltage provided by the DC / DC converter, and providing an energy storage capacitor voltage feedback signal representing the energy storage capacitor voltage and a system voltage feedback signal representing the system voltage; When the energy storage capacitor voltage feedback signal is less than the energy storage capacitor low voltage reference and the system voltage feedback signal is greater than the system full voltage reference, controlling the bidirectional switch circuit to charge the energy storage capacitor; as well as When the energy storage capacitor voltage feedback signal is greater than the energy storage capacitor full voltage reference and the system voltage feedback signal is less than the system low voltage reference, the bidirectional switch circuit is controlled to discharge the energy storage capacitor.

10. The control method according to claim 9, wherein: When the bidirectional switch circuit charges the energy storage capacitor, the bidirectional switch circuit operates in a boost mode; and When the bidirectional switch circuit discharges the energy storage capacitor, the bidirectional switch circuit operates in a buck mode.

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