Switching power supply and power management control circuit therefor

Abstract

The application discloses a switching power supply and a power management control circuit thereof. The switching power supply is used for converting an AC input voltage into a first DC output voltage under the control of the power management control circuit. The power management control circuit comprises a drive control circuit, a power switch controlled by the drive control circuit to be turned on and turned off, and a first DC conversion circuit receiving the first DC output voltage and converting the first DC output voltage into a second DC output voltage. The switching power supply provided by the application has the first DC conversion circuit built in the switching power supply, and the first DC output voltage is converted into other DC output voltages, so that the transformer design, peripheral devices, stability of multi-output voltages and the like of the switching power supply are optimized and improved.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, and in particular to a multi-output switching power supply and its power management control circuit. Background Technology

[0002] With the advent of the era of electrification and intelligence, many electronic devices often require multiple DC power supplies of different voltages to power different circuit modules. This means that the power supply needs to meet the power supply requirements of different circuit units, and multi-output switching power supplies are being used more and more widely in power electronic devices.

[0003] Multi-output switching power supplies face many challenges in the design and development phase, such as the increased complexity of transformer multi-output design and winding, and the poor cross-regulation of multi-output power supplies. Utility Model Content

[0004] In view of the above problems, the purpose of this disclosure is to provide a switching power supply that improves the stability of each output voltage and reduces the cost of peripheral components of the switching power supply.

[0005] According to a first aspect of this disclosure, a switching power supply is provided that converts an AC input voltage into a first DC output voltage under the control of a power management control circuit, the power management control circuit comprising:

[0006] Drive control circuit;

[0007] A power switch, wherein the drive control circuit controls the power switch to be turned on and off;

[0008] The first DC-DC converter circuit receives the first DC output voltage and converts the first DC output voltage into a second DC output voltage.

[0009] Optionally, it also includes:

[0010] The second DC-DC converter circuit receives the first DC output voltage and converts the first DC output voltage into a third DC output voltage.

[0011] Optionally, the first DC-DC conversion circuit is a first charge pump circuit.

[0012] Optionally, the first DC-DC conversion circuit is a boost circuit.

[0013] Optionally, the first charge pump circuit includes:

[0014] The first pump capacitor and the second pump capacitor are connected in series;

[0015] A first switch array forms a charging circuit with the first pump capacitor and the second pump capacitor, and a discharging circuit with the first pump capacitor. In the charging circuit, the first pump capacitor and the second pump capacitor are connected in series between the first DC output voltage and ground to charge the first pump capacitor and the second pump capacitor. In the discharging circuit, the first pump capacitor is connected between the first DC output voltage and the second DC output voltage to superimpose the voltage on the first pump capacitor onto the first DC output voltage, thereby generating the second DC output voltage.

[0016] Optionally, the first charge pump circuit includes:

[0017] Third pump capacitor;

[0018] The second switch array forms a charging circuit and a discharging circuit with the third pump capacitor. The charging circuit receives the first DC output voltage to charge the third pump capacitor, and the discharging circuit discharges the third pump capacitor to superimpose the voltage on the third pump capacitor onto the first DC output voltage, thereby generating the second DC output voltage.

[0019] A voltage regulator, connected to the second switch array, generates a first error amplification signal based on a voltage signal characterizing the second DC output voltage and a first reference voltage;

[0020] A logic control unit, connected to the voltage regulator and the second switch array, generates a control signal based on the first error amplification signal to control the conduction of the charging circuit or the discharging circuit.

[0021] Optionally, the first switch array includes:

[0022] A first switch is connected between the first DC output voltage and the first terminal of the second pump capacitor;

[0023] The second switch is connected between the second terminal of the second pump capacitor and the second DC output voltage.

[0024] The third switch is connected between the second terminal of the first pump capacitor and ground;

[0025] A fourth switch is connected between the second terminal of the first pump capacitor and the first DC output voltage.

[0026] The second terminal of the second pump capacitor is connected to the first terminal of the first pump capacitor.

[0027] The first switch is turned on, the third switch is turned on, and together with the first pump capacitor and the second pump capacitor, they form the charging circuit; the fourth switch is turned on, the second switch is turned on, and together with the first pump capacitor, they form the discharging circuit.

[0028] Optionally, the second switch array includes:

[0029] The fifth switch is connected between the first DC output voltage and the first terminal of the third pump capacitor;

[0030] The sixth switch is connected between the second terminal of the third pump capacitor and ground;

[0031] The seventh switch is connected between the first terminal of the third pump capacitor and the second DC output voltage;

[0032] The eighth switch is connected between the first DC output voltage and the second terminal of the third pump capacitor.

[0033] The fifth switch is turned on, the sixth switch is turned on, and together with the third pump capacitor, they form the charging circuit; the eighth switch is turned on, the seventh switch is turned on, and together with the third pump capacitor, they form the discharging circuit.

[0034] Optionally, the first charge pump circuit and the drive control circuit are integrated in the same chip, and the pump capacitor in the first charge pump circuit is placed outside the chip.

[0035] Optionally, the power switch is integrated with the first charge pump circuit and the drive control circuit in the same chip, and the pump capacitor in the first charge pump circuit is placed outside the chip.

[0036] Optionally, the boost circuit includes:

[0037] The first inductor receives the first DC output voltage at its first terminal.

[0038] The first switching transistor has a first terminal grounded through a sampling resistor, and the second terminal of the first switching transistor is connected to the second terminal of the first inductor.

[0039] The second switching transistor has its first terminal connected to the second terminal of the first inductor, and its second terminal serves as the output terminal of the boost circuit to output the second DC output voltage.

[0040] A first control circuit is connected to the output terminal of the boost circuit, the control terminal of the first switch, and the control terminal of the second switch. It samples the output terminal of the boost circuit and generates an error amplification signal based on the sampled signal and a reference voltage. The error amplification signal is compared with the current sampling signal of the first switch to generate a drive signal for the first switch and a drive signal for the second switch to control the boost circuit to convert the first DC output voltage into the second DC output voltage.

[0041] Optionally, the boost circuit includes:

[0042] The first inductor receives the first DC output voltage at its first terminal.

[0043] The first switching transistor has a first terminal grounded through a sampling resistor, and the second terminal of the first switching transistor is connected to the second terminal of the first inductor.

[0044] A freewheeling diode, wherein the first end of the freewheeling diode is connected to the second end of the first inductor, and the second end of the freewheeling diode serves as the output terminal of the boost circuit to output the second DC output voltage;

[0045] The second control circuit is connected to the output terminal of the boost circuit and the control terminal of the first switching transistor. It samples the output terminal of the boost circuit and generates an error amplification signal based on the sampled signal and the reference voltage. The error amplification signal is compared with the current sampling signal of the first switching transistor to generate a drive signal for the first switching transistor to control the boost circuit to convert the first DC output voltage into the second DC output voltage.

[0046] Optionally, the boost circuit and the drive control circuit are integrated in the same chip, and the first inductor in the boost circuit is placed outside the chip, or the first inductor and the freewheeling diode in the boost circuit are placed outside the chip.

[0047] Optionally, the power switch is integrated with the boost circuit and the drive control circuit in the same chip, and the first inductor in the boost circuit is placed outside the chip, or the first inductor and the freewheeling diode in the boost circuit are placed outside the chip.

[0048] Optionally, the second DC-DC converter circuit is a low-dropout linear regulator circuit.

[0049] Optionally, the second DC-DC conversion circuit is a second charge pump circuit.

[0050] Optionally, the low-dropout linear regulator circuit and the drive control circuit are integrated into the same chip.

[0051] Optionally, the low-dropout linear regulator circuit is integrated with the drive control circuit in the same chip, and is also integrated with at least one of the power switch and the first DC-DC conversion circuit in the same chip.

[0052] Optionally, the second charge pump circuit and the drive control circuit are integrated in the same chip, and the pump capacitor in the second charge pump circuit is placed outside the chip.

[0053] Optionally, the second charge pump circuit is integrated with the drive control circuit in the same chip, and is also integrated with at least one of the power switch and the first DC-DC conversion circuit in the same chip, with the pump capacitor in the second charge pump circuit located outside the chip.

[0054] Optionally, the low-dropout linear regulator circuit includes:

[0055] The third switching transistor is connected between the first DC output voltage and the third DC output voltage;

[0056] The fourth switch is connected between the first DC output voltage and the control terminal of the third switch;

[0057] The fifth switch is connected between the first DC output voltage and the control terminal of the fourth switch;

[0058] A first error amplifier receives a voltage signal characterizing the third DC output voltage and a reference voltage, and outputs a second error amplification signal characterizing the third DC output voltage and the reference voltage, which is then provided to the control terminal of the fifth switching transistor; and

[0059] A DC constant current source is connected between the control terminal of the fifth switching transistor and ground.

[0060] Optionally, the second charge pump circuit includes:

[0061] Fourth pump capacitor, fifth pump capacitor;

[0062] The third switch array forms a charging circuit with the fourth and fifth pump capacitors, and a discharging circuit with the fourth and fifth pump capacitors. In the charging circuit, the fourth and fifth pump capacitors are connected in series between the first DC output voltage and ground to charge the fourth and fifth pump capacitors. In the discharging circuit, the fourth and fifth pump capacitors are connected in parallel between the third DC output voltage and ground to output the third DC output voltage.

[0063] Optionally, the third switch array includes:

[0064] The ninth switch is connected between the first DC output voltage and the first terminal of the fourth pump capacitor;

[0065] The tenth switch is connected between the first terminal of the fourth pump capacitor and the first terminal of the fifth pump capacitor.

[0066] The eleventh switch is connected between the second terminal of the fourth pump capacitor and the first terminal of the fifth pump capacitor.

[0067] The twelfth switch is connected between the second terminal of the fourth pump capacitor and ground.

[0068] The first terminal of the fifth pump capacitor is connected to the third DC output voltage, and the second terminal of the fifth pump capacitor is grounded.

[0069] The ninth switch and the eleventh switch are turned on, forming the charging circuit with the fourth pump capacitor and the fifth pump capacitor. The tenth switch and the twelfth switch are turned on, forming the discharging circuit with the fourth pump capacitor and the fifth pump capacitor.

[0070] Optionally, it also includes:

[0071] A flyback converter or buck converter, under the control of a power management control circuit, converts the AC input voltage into a first DC output voltage.

[0072] Optionally, the flyback converter circuit includes:

[0073] The rectifier unit rectifies the AC input voltage and outputs a rectified voltage;

[0074] The transformer includes an input winding and an output winding. The first end of the input winding is connected to the rectifier unit to receive the rectified voltage, and the second end of the input winding is connected to the second end of the power switch. The output winding outputs the first DC output voltage after rectification and filtering.

[0075] A first diode, the anode of which is connected to the first end of the output winding;

[0076] A first capacitor is connected between the second end of the output winding and the cathode of the first diode.

[0077] Optionally, the flyback converter circuit further includes:

[0078] A first resistor, the first end of which is connected to the first end of the input winding;

[0079] A second capacitor, the first end of which is connected to the first end of the input winding;

[0080] The second diode has its anode connected to the second end of the input winding, and its cathode connected to the second end of the first resistor and the second end of the second capacitor.

[0081] The second resistor and the third capacitor are connected in series between the anode and the cathode of the first diode.

[0082] Optionally, the transformer further includes an auxiliary winding, the auxiliary winding and the input winding being located on the primary side of the transformer, and the output winding being located on the secondary side of the transformer. The auxiliary winding provides a power supply voltage to the drive control circuit. The flyback converter circuit further includes:

[0083] A fourth diode, wherein the anode of the fourth diode is connected to the second end of the auxiliary winding;

[0084] The fifth capacitor is connected between the first end of the auxiliary winding and the cathode of the fourth diode, and the cathode of the fourth diode also provides the power supply voltage.

[0085] Optionally, it also includes:

[0086] A third resistor, the input section of the optocoupler, an adjustable precision voltage regulator, a fourth resistor, and a fifth resistor are connected in series between the first DC output voltage and the first charge pump circuit; and

[0087] The first connection node is connected in series between the input section of the optocoupler and the adjustable precision regulator, and the sixth resistor and sixth capacitor are connected in series between the second connection node between the fourth resistor and the fifth resistor.

[0088] Optionally, the drive control circuit generates a gate drive signal for the power switch based on the supply voltage and a voltage signal characterizing the first DC output voltage, wherein the supply voltage is provided by the second DC output voltage output by the first DC conversion circuit.

[0089] Optionally, the buck circuit includes:

[0090] A rectifier bridge, the input of which receives an AC input voltage, and the output of which provides a rectified voltage and is connected to the second terminal of the power switch;

[0091] The second inductor has its first end connected to the first end of the power switch and its second end connected to the first DC output voltage.

[0092] The fifth diode, wherein the cathode of the fifth diode is connected to the first terminal of the second inductor;

[0093] The seventh capacitor has its first terminal connected to the second terminal of the second inductor, and its second terminal connected to the anode of the fifth diode and grounded.

[0094] Optionally, the power management control circuit includes a DC input terminal and a sampling terminal. The second terminal of the power switch is connected to the DC input terminal, and the first terminal of the power switch is grounded via the sampling terminal and a sampling resistor. The control terminal of the power switch receives the gate drive signal generated by the drive control circuit.

[0095] Optionally, the drive control circuit, the power switch, the first DC-DC conversion circuit, and the second DC-DC conversion circuit are integrated into the same chip.

[0096] According to another aspect of this application, a power management control circuit for a switching power supply is provided, comprising:

[0097] Drive control circuit;

[0098] A power switch, wherein the drive control circuit controls the power switch to be turned on and off;

[0099] The first DC-DC converter circuit receives the first DC output voltage and converts the first DC output voltage into a second DC output voltage.

[0100] Optionally, it also includes:

[0101] The second DC-DC converter circuit receives the first DC output voltage and converts the first DC output voltage into a third DC output voltage.

[0102] Optionally, the first DC-DC conversion circuit is a first charge pump circuit.

[0103] Optionally, the first DC-DC conversion circuit is a boost circuit.

[0104] Optionally, the first charge pump circuit includes:

[0105] The first pump capacitor and the second pump capacitor are connected in series;

[0106] A first switch array forms a charging circuit with the first pump capacitor and the second pump capacitor, and a discharging circuit with the first pump capacitor. In the charging circuit, the first pump capacitor and the second pump capacitor are connected in series between the first DC output voltage and ground to charge the first pump capacitor and the second pump capacitor. In the discharging circuit, the first pump capacitor is connected between the first DC output voltage and the second DC output voltage to superimpose the voltage on the first pump capacitor onto the first DC output voltage, thereby generating the second DC output voltage.

[0107] Optionally, the first charge pump circuit includes:

[0108] Third pump capacitor;

[0109] The second switch array forms a charging circuit and a discharging circuit with the third pump capacitor. The charging circuit receives the first DC output voltage to charge the third pump capacitor, and the discharging circuit discharges the third pump capacitor to superimpose the voltage on the third pump capacitor onto the first DC output voltage, thereby generating the second DC output voltage.

[0110] A voltage regulator, connected to the second switch array, generates a first error amplification signal based on a voltage signal characterizing the second DC output voltage and a first reference voltage;

[0111] A logic control unit, connected to the voltage regulator and the second switch array, generates a control signal based on the first error amplification signal to control the conduction of the charging circuit or the discharging circuit.

[0112] Optionally, the first switch array includes:

[0113] A first switch is connected between the first DC output voltage and the first terminal of the second pump capacitor;

[0114] The second switch is connected between the second terminal of the second pump capacitor and the second DC output voltage.

[0115] The third switch is connected between the second terminal of the first pump capacitor and ground;

[0116] A fourth switch is connected between the second terminal of the first pump capacitor and the first DC output voltage.

[0117] The second terminal of the second pump capacitor is connected to the first terminal of the first pump capacitor.

[0118] The first switch is turned on, the third switch is turned on, and together with the first pump capacitor and the second pump capacitor, they form the charging circuit; the fourth switch is turned on, the second switch is turned on, and together with the first pump capacitor, they form the discharging circuit.

[0119] Optionally, the second switch array includes:

[0120] The fifth switch is connected between the first DC output voltage and the first terminal of the third pump capacitor;

[0121] The sixth switch is connected between the second terminal of the third pump capacitor and ground;

[0122] The seventh switch is connected between the first terminal of the third pump capacitor and the second DC output voltage;

[0123] The eighth switch is connected between the first DC output voltage and the second terminal of the third pump capacitor.

[0124] The fifth switch is turned on, the sixth switch is turned on, and together with the third pump capacitor, they form the charging circuit; the eighth switch is turned on, the seventh switch is turned on, and together with the third pump capacitor, they form the discharging circuit.

[0125] Optionally, the first charge pump circuit and the drive control circuit are integrated in the same chip, and the pump capacitor in the first charge pump circuit is placed outside the chip.

[0126] Optionally, the power switch is integrated with the first charge pump circuit and the drive control circuit in the same chip, and the pump capacitor in the first charge pump circuit is placed outside the chip.

[0127] Optionally, the boost circuit includes:

[0128] The first inductor receives the first DC output voltage at its first terminal.

[0129] The first switching transistor has a first terminal grounded through a sampling resistor, and the second terminal of the first switching transistor is connected to the second terminal of the first inductor.

[0130] The second switching transistor has its first terminal connected to the second terminal of the first inductor, and its second terminal serves as the output terminal of the boost circuit to output the second DC output voltage.

[0131] A first control circuit is connected to the output terminal of the boost circuit, the control terminal of the first switch, and the control terminal of the second switch. It samples the output terminal of the boost circuit and generates an error amplification signal based on the sampled signal and a reference voltage. The error amplification signal is compared with the current sampling signal of the first switch to generate a drive signal for the first switch and a drive signal for the second switch to control the boost circuit to convert the first DC output voltage into the second DC output voltage.

[0132] Optionally, the boost circuit includes:

[0133] The first inductor receives the first DC output voltage at its first terminal.

[0134] The first switching transistor has a first terminal grounded through a sampling resistor, and the second terminal of the first switching transistor is connected to the second terminal of the first inductor.

[0135] A freewheeling diode, wherein the first end of the freewheeling diode is connected to the second end of the first inductor, and the second end of the freewheeling diode serves as the output terminal of the boost circuit to output the second DC output voltage;

[0136] The second control circuit is connected to the output terminal of the boost circuit and the control terminal of the first switching transistor. It samples the output terminal of the boost circuit and generates an error amplification signal based on the sampled signal and the reference voltage. The error amplification signal is compared with the current sampling signal of the first switching transistor to generate a drive signal for the first switching transistor to control the boost circuit to convert the first DC output voltage into the second DC output voltage.

[0137] Optionally, the boost circuit and the drive control circuit are integrated in the same chip, and the first inductor in the boost circuit is placed outside the chip, or the first inductor and the freewheeling diode in the boost circuit are placed outside the chip.

[0138] Optionally, the power switch is integrated with the boost circuit and the drive control circuit in the same chip, and the first inductor in the boost circuit is placed outside the chip, or the first inductor and the freewheeling diode in the boost circuit are placed outside the chip.

[0139] Optionally, the second DC-DC converter circuit is a low-dropout linear regulator circuit.

[0140] Optionally, the second DC-DC conversion circuit is a second charge pump circuit.

[0141] Optionally, the low-dropout linear regulator circuit and the drive control circuit are integrated into the same chip.

[0142] Optionally, the low-dropout linear regulator circuit is integrated with the drive control circuit in the same chip, and is also integrated with at least one of the power switch and the first DC-DC conversion circuit in the same chip.

[0143] Optionally, the second charge pump circuit and the drive control circuit are integrated in the same chip, and the pump capacitor in the second charge pump circuit is placed outside the chip.

[0144] Optionally, the second charge pump circuit is integrated with the drive control circuit in the same chip, and is also integrated with at least one of the power switch and the first DC-DC conversion circuit in the same chip, with the pump capacitor in the second charge pump circuit located outside the chip.

[0145] Optionally, the low-dropout linear regulator circuit includes:

[0146] The third switching transistor is connected between the first DC output voltage and the third DC output voltage;

[0147] The fourth switch is connected between the first DC output voltage and the control terminal of the third switch;

[0148] The fifth switch is connected between the first DC output voltage and the control terminal of the fourth switch;

[0149] A first error amplifier receives a voltage signal characterizing the third DC output voltage and a reference voltage, and outputs a second error amplification signal characterizing the third DC output voltage and the reference voltage, which is then provided to the control terminal of the fifth switching transistor; and

[0150] A DC constant current source is connected between the control terminal of the fifth switching transistor and ground.

[0151] Optionally, the second charge pump circuit includes:

[0152] Fourth pump capacitor, fifth pump capacitor;

[0153] The third switch array forms a charging circuit with the fourth and fifth pump capacitors, and a discharging circuit with the fourth and fifth pump capacitors. In the charging circuit, the fourth and fifth pump capacitors are connected in series between the first DC output voltage and ground to charge the fourth and fifth pump capacitors. In the discharging circuit, the fourth and fifth pump capacitors are connected in parallel between the third DC output voltage and ground to output the third DC output voltage.

[0154] Optionally, the third switch array includes:

[0155] The ninth switch is connected between the first DC output voltage and the first terminal of the fourth pump capacitor;

[0156] The tenth switch is connected between the first terminal of the fourth pump capacitor and the first terminal of the fifth pump capacitor.

[0157] The eleventh switch is connected between the second terminal of the fourth pump capacitor and the first terminal of the fifth pump capacitor.

[0158] The twelfth switch is connected between the second terminal of the fourth pump capacitor and ground.

[0159] The first terminal of the fifth pump capacitor is connected to the third DC output voltage, and the second terminal of the fifth pump capacitor is grounded.

[0160] The ninth switch and the eleventh switch are turned on, forming the charging circuit with the fourth pump capacitor and the fifth pump capacitor. The tenth switch and the twelfth switch are turned on, forming the discharging circuit with the fourth pump capacitor and the fifth pump capacitor.

[0161] Optionally, the drive control circuit generates a gate drive signal for the power switch based on the supply voltage and a voltage signal characterizing the first DC output voltage, wherein the supply voltage is provided by the second DC output voltage output by the first DC conversion circuit.

[0162] Optionally, the power management control circuit includes a DC input terminal and a sampling terminal. The second terminal of the power switch is connected to the DC input terminal, and the first terminal of the power switch is grounded via the sampling terminal and a sampling resistor. The control terminal of the power switch receives the gate drive signal generated by the drive control circuit.

[0163] Optionally, the drive control circuit, the power switch, the first DC-DC conversion circuit, and the second DC-DC conversion circuit are integrated into the same chip.

[0164] The switching power supply disclosed herein integrates a DC-DC conversion circuit into the switching power supply, and uses the first DC output voltage generated in the switching power supply as the input DC voltage of the DC-DC conversion circuit. The DC-DC conversion circuit then generates at least one DC output voltage required by the low-power application circuit unit. This optimizes and improves the transformer design, peripheral components, and stability of the multi-output voltages in the multi-output switching power supply.

[0165] Furthermore, integrating the DC-DC conversion circuit with the drive control circuit simplifies the transformer design of the switching power supply, improves the stability of each output voltage, and reduces the cost of peripheral components in the system solution. Attached Figure Description

[0166] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the present invention with reference to the accompanying drawings, in which:

[0167] Figure 1 A schematic diagram of an existing switching power supply is shown.

[0168] Figure 2 This diagram shows a structural schematic of a switching power supply provided in the first embodiment of the present invention.

[0169] Figure 3 This diagram shows a structural schematic of a switching power supply provided in the second embodiment of the present invention.

[0170] Figure 4 This diagram illustrates the structure of a switching power supply according to the third embodiment of the present invention.

[0171] Figure 5 This diagram shows a structural schematic of a switching power supply provided in the fourth embodiment of the present invention;

[0172] Figure 6 This diagram illustrates the structure of a switching power supply according to the fifth embodiment of the present invention.

[0173] Figure 7 This diagram illustrates the structure of a switching power supply according to the sixth embodiment of the present invention.

[0174] Figure 8 This diagram shows a structural schematic of a switching power supply provided in the seventh embodiment of the present invention;

[0175] Figure 9 This diagram shows a structural schematic of a switching power supply provided in the eighth embodiment of the present invention;

[0176] Figure 10 This diagram shows a structural schematic of a switching power supply provided in the ninth embodiment of the present invention;

[0177] Figure 11 This diagram illustrates the structure of a switching power supply according to the tenth embodiment of the present invention.

[0178] Figure 12 This diagram illustrates the structure of a switching power supply according to the eleventh embodiment of the present invention.

[0179] Figure 13This diagram shows a structural schematic of a first charge pump circuit provided by the present invention.

[0180] Figure 14 This diagram shows a drive control circuit and a first DC-DC conversion circuit provided by the present invention.

[0181] Figure 15 This diagram illustrates a low-dropout linear voltage regulator circuit provided by this invention.

[0182] Figure 16 This invention provides a schematic diagram of another first charge pump circuit.

[0183] Figure 17 This diagram shows a structural schematic of a second charge pump circuit provided by the present invention. Detailed Implementation

[0184] Various embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0185] Figure 1 A schematic diagram of an existing switching power supply is shown.

[0186] like Figure 1 As shown, the switching power supply is used to convert the AC input voltage Vin into multiple DC output voltages (including the first DC output voltage Vout1, the second DC output voltage Vout2, and the third DC output voltage Vout3).

[0187] The switching power supply includes a main circuit 10 and a drive control and switching transistor circuit 20.

[0188] The main circuit 10 is a flyback converter that receives AC input voltage Vin and controls the primary side of the flyback converter through drive control and switching transistor circuit 20 so that the secondary side outputs the first DC output voltage Vout1, the second DC output voltage Vout2, and the third DC output voltage Vout3.

[0189] The drive control and switching circuit 20 includes a sampling terminal CS, a feedback terminal FB, a DC input terminal DRAIN, a power supply terminal VCC, and a ground terminal GND.

[0190] The main circuit 10 includes a rectifier bridge and a transformer T0. The rectifier bridge receives the AC input voltage Vin and outputs a rectified voltage. The transformer T0 includes an input winding, an auxiliary winding, and first to third output windings. The first end of the input winding is connected to the rectifier bridge to receive the rectified voltage, and the second end of the input winding is connected to the DC input terminal DRAIN of the drive control and switching transistor circuit 20. A resistor R1, a diode D2, and a capacitor C2 connected in parallel with the resistor R1 are also connected in series across the two ends of the input winding. The first end of the auxiliary winding is grounded, and the second end of the auxiliary winding is connected to the power supply terminal VCC of the drive control and switching transistor circuit 20. A capacitor C5 and a diode D4 are also connected in series across the two ends of the auxiliary winding. The first output winding outputs a first DC output voltage Vout1. A capacitor C1, a diode D1, a resistor R2, and a capacitor C3 are also connected in series across the diode D1. The second output winding outputs a second DC output voltage Vout2. A capacitor C11 and a diode D5 are also connected in series across the two ends of the second output winding. The third output winding outputs a third DC output voltage Vout3. A capacitor C10 and a diode D3 are connected in series across the third output winding. The sampling terminal CS of the drive control and switching transistor circuit 20 is grounded via resistor R5, and the grounding terminal GND is grounded. The feedback terminal FB is grounded via capacitor C8. Resistors R3 and R4 are connected in series between the first DC output voltage Vout1 and ground. The feedback terminal FB is also connected to the junction of resistors R3 and R4.

[0191] This embodiment employs multiple secondary windings and auxiliary windings, with each secondary winding corresponding to one output, and the auxiliary winding supplying power to the drive control and switching transistor circuits. This multiple winding configuration makes the transformer very complex and costly, and changes in the load of one output can affect the voltage accuracy of another, resulting in poor cross-regulation. If a stable output voltage is required, additional voltage regulator circuitry and more peripheral components are needed, increasing the overall system cost.

[0192] In practical applications, multi-output switching power supplies typically have relatively low output power for the main control output, while the output power of the other outputs is generally lower. Based on this, this application integrates a DC-DC converter circuit into the switching power supply. The first DC output voltage, obtained by converting the AC input voltage from the main circuit of the switching power supply, is used as the input voltage for the DC-DC converter circuit. This DC-DC converter then generates the supply voltage required by the low-power application circuit units. The technical solution of this application optimizes and improves the transformer design, peripheral components, and stability of the multi-output voltages in multi-output switching power supplies.

[0193] The switching power supply of this application converts an AC input voltage into a first DC output voltage under the control of a power management control circuit. The power management control circuit includes: a drive control circuit; a power switch, the drive control circuit controlling the power switch to turn on and off; and a first DC-DC conversion circuit, which receives the first DC output voltage and converts the first DC output voltage into a second DC output voltage.

[0194] Furthermore, it also includes a second DC-DC conversion circuit that receives the first DC output voltage and converts the first DC output voltage into a third DC output voltage.

[0195] Furthermore, the first DC-DC conversion circuit is a first charge pump circuit or a boost circuit, and the first DC-DC conversion circuit is integrated with the drive control circuit on the same chip. Furthermore, the first DC-DC conversion circuit, the drive control circuit, and the power switch are integrated on the same chip.

[0196] For example, the first charge pump circuit and the drive control circuit are integrated into the same chip, and the pump capacitor in the first charge pump circuit is located outside the chip. Alternatively, the power switch is integrated into the same chip as the first charge pump circuit and the drive control circuit, and the pump capacitor in the first charge pump circuit is located outside the chip. Alternatively, the first charge pump circuit and the drive control circuit are discrete chips.

[0197] For example, the boost circuit and the drive control circuit are integrated into the same chip, with the first inductor in the boost circuit located outside the chip, or the first inductor and the freewheeling diode in the boost circuit located outside the chip. Alternatively, the power switch is integrated with the boost circuit and the drive control circuit into the same chip, with the first inductor in the boost circuit located outside the chip, or the first inductor and the freewheeling diode in the boost circuit located outside the chip. Alternatively, the boost circuit and the drive control circuit are discrete chips.

[0198] Furthermore, the second DC-DC conversion circuit is a low-dropout linear regulator circuit or a second charge pump circuit. The second DC-DC conversion circuit and the drive control circuit are either independently integrated or integrated into one unit.

[0199] For example, the low-dropout linear regulator circuit and the drive control circuit are integrated on the same chip. Alternatively, the low-dropout linear regulator circuit and the drive control circuit, along with at least one of the power switch and the first DC-DC conversion circuit, are integrated on the same chip. Alternatively, the low-dropout linear regulator circuit and the drive control circuit are discrete chips.

[0200] For example, the second charge pump circuit and the drive control circuit are integrated on the same chip, and the pump capacitor in the second charge pump circuit is located outside the chip. Alternatively, the second charge pump circuit and the drive control circuit are integrated on the same chip, and at least one of the power switch and the first DC-DC conversion circuit is also integrated on the same chip, with the pump capacitor in the second charge pump circuit located externally. Alternatively, the second charge pump circuit and the drive control circuit are discrete chips.

[0201] For example, the drive control circuit, power switch, first DC-DC conversion circuit, and second DC-DC conversion circuit are integrated into the same chip.

[0202] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples.

[0203] Figure 2 This diagram shows a structural schematic of a switching power supply provided in the first embodiment of the present invention. Figure 13 This diagram shows a structural schematic of a first charge pump circuit provided by the present invention. Figure 14 This diagram shows a drive control circuit and a first DC-DC conversion circuit provided by the present invention. Figure 15 This diagram shows a low-dropout linear voltage regulator circuit provided by the present invention.

[0204] like Figure 2 As shown, the switching power supply 100 in the first embodiment is used to convert AC input voltage into DC voltage and to provide at least a first DC output voltage Vout1, a second DC output voltage Vout2, and a third DC output voltage Vout3.

[0205] The switching power supply 100 includes a main circuit 110, a power management control circuit, and a second DC-DC conversion circuit 140.

[0206] For example, the power management control circuit includes a drive control and power switch circuit 120 and a first DC-DC conversion circuit 130. The drive control and power switch circuit 120 includes a power switch Q0 and a drive control circuit 121. Alternatively, the drive control circuit and the power switch can be discretely integrated in the power management control circuit.

[0207] In the switching power supply 100, the first DC-DC conversion circuit 130 is a first charge pump circuit, and the second DC-DC conversion circuit 140 is a low-dropout linear regulator circuit. The first charge pump circuit, drive control and power switch circuit 120, and power switch are integrated into the same chip, and the pump capacitor in the first charge pump circuit is external. The low-dropout linear regulator circuit and the power management control circuit are discrete chips.

[0208] The main circuit 110 receives the AC input voltage Vin and, under the control of the power management control circuit, converts the AC input voltage Vin into the first DC output voltage Vout1 and outputs it.

[0209] The drive control circuit controls the power switch to turn on and off. When the power switch is on, the second terminal of the power switch is connected to the first terminal of the power switch and then connected to ground through the sampling resistor. This controls the main circuit 110 to convert the AC input voltage Vin into the first DC output voltage Vout1.

[0210] The first charge pump circuit is connected to the main circuit 110, receives the first DC output voltage Vout1, and boosts the first DC output voltage Vout1 to output the second DC output voltage Vout2.

[0211] The low-dropout linear regulator circuit is connected to the main circuit 110, receives the first DC output voltage Vout1, and steps down the first DC output voltage Vout1 to output the third DC output voltage Vout3.

[0212] For example, the main circuit 110 is a flyback converter circuit. It includes a rectifier unit, a transformer T1, a first diode D1, and a first capacitor C1. The rectifier unit, for example, includes a rectifier bridge to rectify the AC input voltage Vin and output a rectified voltage. The two input terminals of the rectifier bridge receive the AC input voltage Vin, one output terminal outputs the rectified voltage, and the other output terminal is grounded. The transformer T1 includes an input winding and an output winding. The first terminal of the input winding is connected to the rectifier unit to receive the rectified voltage, and the second terminal of the input winding is connected to the second terminal of a power switch. The two ends of the output winding are rectified and filtered to output a first DC output voltage Vout1. The anode of the first diode D1 is connected to the first terminal of the output winding. The first capacitor C1 is connected between the second terminal of the output winding and the cathode of the first diode D1.

[0213] Energy storage stage of the main circuit: The power switch is turned on, current flows through the input winding of transformer T1, and energy is stored in the magnetic field of transformer T1. At this time, since the first diode D1 is reverse biased, no current flows in the first output winding, and the first DC output voltage Vout1 is the voltage across the first capacitor C1.

[0214] The main circuit's energy release phase: When the power switch is turned off, the energy stored in transformer T1 is transferred to the first output winding through mutual inductance. During this phase, the generated voltage charges the first capacitor C1 after passing through the first diode D1 and outputs the first DC output voltage Vout1.

[0215] Furthermore, the main circuit also includes a first resistor R1, a second capacitor C2, and a second diode D2 across the input winding. The first terminal of the first resistor R1 is connected to the first terminal of the input winding. The first terminal of the second capacitor C2 is also connected to the first terminal of the input winding. The anode of the second diode D2 is connected to the second terminal of the input winding, and the cathode of the second diode D2 is connected to the second terminal of the first resistor R1 and the second terminal of the second capacitor C2. The main circuit also includes an RC network across the first diode D1, comprising a second resistor R2 and a third capacitor C3, connected in series between the anode and cathode of the first diode D1. A capacitor C0 is also connected between the two output terminals of the rectifier bridge for filtering.

[0216] The drive control and power switching circuit 120 and the first charge pump circuit 130 are integrated into a single power management control circuit chip. The power management control circuit includes a sampling terminal CS, a feedback terminal FB, a ground terminal GND, an input terminal VIN, a capacitor terminal C-, a capacitor terminal C+, an output terminal VOUT, a power supply terminal VCC, and a DC input terminal DRAIN.

[0217] Further, see Figure 13 The first charge pump circuit 130 includes a second switch array, a voltage regulator, a logic control unit, and a third pump capacitor C13 disposed peripherally. The switch array and the third pump capacitor C13 form a charging circuit and a discharging circuit. The charging circuit receives a first DC output voltage Vout1 to charge the third pump capacitor C13, and the discharging circuit discharges the third pump capacitor C13 to superimpose the voltage on the third pump capacitor C13 onto the first DC output voltage Vout1, thereby outputting a second DC output voltage Vout2. The voltage regulator is connected to the switch array and generates a first error amplification signal based on the voltage signal characterizing the second DC output voltage Vout2 and a first reference voltage. The logic control unit is connected to the voltage regulator and the switch array and generates a control signal based on the first error amplification signal to control the conduction of the charging circuit or the discharging circuit. The logic control unit controls the conduction time and duty cycle of the charging circuit and the discharging circuit to achieve voltage conversion. The logic control unit of this application can be implemented using conventional circuits. The control principle of the logic control unit is not the main part of this application and will not be described in detail.

[0218] like Figure 14As shown, the drive control circuit 121 is connected to the control terminal of the power switch Q0. The drive control circuit 121 is also connected to the power supply terminal VCC and the feedback terminal FB, and generates the gate drive signal of the power switch Q0 based on the power supply voltage and the voltage signal characterizing the first DC output voltage Vout1. The drive control circuit 121 is also connected to the ground terminal GND. The second terminal of the power switch Q0 is connected to the DC input terminal DRAIN, and then to the second terminal of the input winding of the transformer T1. The first terminal of the power switch Q0 is connected to the sampling terminal CS. The power supply voltage is provided by the main circuit 110 or by the first charge pump circuit 130.

[0219] Furthermore, the peripheral components of the power management control circuit also include: a seventh capacitor C7, an eighth capacitor C8, and resistors R3 to R5. Resistors R3 and R4 are connected in series between the first DC output voltage Vout1 and ground.

[0220] In the switching power supply 100, the supply voltage is provided, for example, by a second DC output voltage Vout2 generated by the first charge pump circuit 130. Furthermore, the power management control circuit also includes a sixth capacitor C6 and a third diode D3 in its peripheral circuitry.

[0221] The input terminal VIN of the power management control circuit is connected to the main circuit 110 to receive the first DC output voltage Vout1 and provides it to the input terminal of the first charge pump circuit 130. Exemplarily, the input terminal of the first charge pump circuit 130 is also grounded via an input capacitor Cin, which can be integrated inside the first charge pump circuit or external to the power management control circuit. The capacitor terminals C+ and C- of the power management control circuit are connected to a third pump capacitor C13 and to the corresponding capacitor terminals in the first charge pump circuit 130. The output terminal VOUT of the power management control circuit is connected to the first charge pump circuit 130 to receive and output the second DC output voltage Vout2, and a seventh capacitor C7 is connected between the output terminal VOUT and ground. Exemplarily, the output terminal of the first charge pump circuit 130 is also grounded via an output capacitor Co, which can be integrated inside the first charge pump circuit 130 or external to the power management control circuit. The power supply terminal VCC of the power management control circuit is connected to the output terminal VOUT via a third diode D3 and provides power supply voltage to the drive control and power switch circuit 120. The power supply terminal VCC of the power management control circuit is also grounded via the sixth capacitor C6. The feedback terminal FB of the power management control circuit is connected to the junction of the third resistor R3 and the fourth resistor R4 to receive the voltage signal representing the first DC output voltage Vout1 and provide it to the drive control circuit. The feedback terminal FB is connected to the ground via the eighth capacitor C8. The sampling terminal CS of the power management control circuit is connected to the first terminal of the power switch Q1 and grounded via the fifth resistor R5. The fifth resistor R5 can also be integrated into the drive control and power switch circuit 120.

[0222] For example, the switch array includes switches S5 to S8, and switches S7, S5, S8, and S6 are connected in series between the output terminal VOUT of the charge pump circuit and ground. The connection node of switches S5 and S8 is connected to the input terminal VIN of the charge pump, the connection node of switches S7 and S5 is connected to the capacitor terminal C+, and the connection node of switches S8 and S6 is connected to the capacitor terminal C-. When switches S5 and S6 are turned on, a charging circuit is formed with the third pump capacitor C13; when switches S8 and S7 are turned on, a discharging circuit is formed with the third pump capacitor C13, thereby superimposing the voltage on the third pump capacitor C13 onto the first DC output voltage Vout1, thus generating a second DC output voltage Vout2.

[0223] The voltage regulator includes a second error amplifier, resistors R5 and R6. Resistors R5 and R6 are connected in series between the output terminal of the charge pump circuit and ground. The connection point of resistors R5 and R6 is connected to the positive input terminal of the second error amplifier. The negative input terminal of the second error amplifier receives a first reference voltage. The output terminal of the second error amplifier outputs a voltage signal representing a second DC output voltage and a first error amplification signal representing the first reference voltage.

[0224] In the first embodiment of this application, a first charge pump circuit is integrated into the power management control circuit. A first DC output voltage is used as the input voltage of the first charge pump circuit, and then the charge pump circuit generates the second DC output voltage required by the low-power application circuit unit. This simplifies the transformer design of the multi-output switching power supply, improves the stability of each output voltage, and reduces the cost of peripheral components in the system solution.

[0225] When the first charge pump circuit is operating, a two-phase non-overlapping clock activates the switch array of the charge pump circuit. In the first clock phase, only switches S5 and S6 are closed, and capacitor C13 is charged to the first DC output voltage Vout1. In the second clock phase, only switches S7 and S8 are closed, and capacitor C13 is connected between the input terminal VIN and the output terminal VOUT of the charge pump circuit. Output voltage regulation is achieved by sampling the second DC output voltage through resistors R5 and R6, comparing it with the first reference voltage VREF through a second error amplifier to generate a first error amplification signal. The logic control circuit then controls the switch array based on this first error amplification signal, thereby achieving a regulated output voltage.

[0226] See Figure 15 The low-dropout linear regulator (LDO) includes: a third switch Q3 connected between a first DC output voltage Vout1 (received by the LDO's input VIN) and a third DC output voltage Vout3 (provided by the LDO's output VOUT). A fourth switch Q4 connected between the first DC output voltage Vout1 and the control terminal of the third switch. A fifth switch Q5 connected between the first DC output voltage Vout1 and the control terminal of the fourth switch Q4. A first error amplifier EA1 receives a voltage signal UQ representing the third DC output voltage Vout3 and a reference voltage Uref, and outputs a second error amplification signal Ur representing the third DC output voltage and the reference voltage, which is then provided to the control terminal of the fifth switch Q5. A DC constant current source is connected between the control terminal of the fifth switch Q5 and ground.

[0227] Q3 and Q4 form a Darlington transistor, and Q5 is the driver transistor. The first error amplifier EA1 amplifies the difference between the voltage signal representing the third DC output voltage and the reference voltage to generate an error voltage Ur (the second error amplification signal), which is used to adjust the voltage drop of the series switching transistors so that the third DC output voltage reaches stability.

[0228] This embodiment integrates a low-dropout linear regulator (LDO) into the switching power supply to convert the first DC output voltage Vout1 into a third DC output voltage Vout3 to power the MCU. The entire switching power supply design allows the transformer T1 to have only one main control output winding, resulting in a simpler circuit structure and lower cost.

[0229] Taking a multi-output power supply in an air conditioner as an example, the 12V output voltage is typically the main power voltage, supplying power to the motor, relays, etc. The 5V output voltage supplies power to the microcontroller, and the 15V output voltage supplies power to the power module (IPM). The first DC output voltage Vout1 is used as the main power voltage, for example, 12V. The second DC output voltage Vout2 is, for example, 15V, and the third DC output voltage Vout3 is, for example, 5V.

[0230] Figure 3 This diagram illustrates the structure of a switching power supply according to a second embodiment of the present invention.

[0231] like Figure 3 As shown, the switching power supply 200, based on the first embodiment, replaces the power supply from the first DC-DC converter 130 to the power supply terminal VCC of the power management control circuit with power supply from the main circuit to the power supply terminal VCC of the power management control circuit. Exemplarily, the flyback converter circuit 210, based on the flyback converter circuit 110, further includes an auxiliary winding, a fourth diode D4, and a fifth capacitor C5 on the primary side of the transformer T1. The anode of the fourth diode D4 is connected to the second end of the auxiliary winding. The fifth capacitor C5 is connected between the first end of the auxiliary winding and the cathode of the fourth diode D4, and the cathode of the fourth diode D4 also provides a power supply voltage.

[0232] Figure 4 This diagram illustrates the structure of a switching power supply according to the third embodiment of the present invention. Figure 16 This invention provides a schematic diagram of another first charge pump circuit.

[0233] like Figure 4 As shown, the switching power supply 300 provided in the third embodiment replaces the first charge pump circuit 130 with the first charge pump circuit 330 based on the first embodiment. It should be noted that the first charge pump circuit 130 in the second embodiment can also be replaced with the first charge pump circuit 330.

[0234] The power management control circuit in the switching power supply 300, based on the power management control circuit of the switching power supply 100, also includes a capacitor terminal Co, and replaces the pump capacitor C13 with pump capacitors C11 and C12 connected in series. The capacitor terminal Co is connected to the connection node of the pump capacitors C11 and C12.

[0235] Combination Figure 16 The first charge pump circuit 330 includes a first pump capacitor C11, a second pump capacitor C12, and a first switch array connected in series. The first switch array forms a charging circuit with the first pump capacitor C11 and the second pump capacitor C12, and a discharging circuit with the first pump capacitor C11. In the charging circuit, the first pump capacitor C11 and the second pump capacitor C12 are connected in series between the first DC output voltage Vout1 and ground, charging the first pump capacitor C11 and the second pump capacitor C12. In the discharging circuit, the first pump capacitor C11 is connected between the first DC output voltage Vout1 and the second DC output voltage Vout2, superimposing the voltage on the first pump capacitor C11 onto the first DC output voltage Vout1, thereby generating the second DC output voltage Vout2.

[0236] The first switch array includes first to fourth switches. The first switch S1 is connected between the input terminal VIN and the capacitor terminal C-, the second switch S2 is connected between the output terminal VOUT and the capacitor terminal Co, the third switch S3 is connected between the ground terminal GND and the capacitor terminal C+, and the fourth switch S4 is connected between the capacitor terminal C+ and the input terminal VIN.

[0237] During the charging cycle, switches S1 and S3 are closed, and switches S2 and S4 are open. The sum of the voltages of the first pump capacitor C11 and the second pump capacitor C12 provides the first DC output voltage Vout1 for the input terminal VIN. If the capacitance values ​​of the first pump capacitor C11 and the second pump capacitor C12 are the same, then the voltage at the midpoint between them is 0.5 * Vout1. During the discharging cycle, switches S2 and S4 are closed, and switches S1 and S3 are open. The first pump capacitor C11 is connected in series between the output terminal VOUT and the input terminal VIN. Therefore, the second DC output voltage Vout2 at the output terminal VOUT = Vout1 + 0.5 * Vout1 = 1.5 * Vout1, thus achieving a voltage conversion of 1.5 times. The first charge pump circuit provided in this embodiment can achieve higher conversion efficiency when converting a 12V input to a 15V output.

[0238] Figure 5 This diagram illustrates the structure of a switching power supply according to the fourth embodiment of the present invention.

[0239] like Figure 5As shown, the switching power supply 400 provided in the fourth embodiment replaces the first charge pump circuit 130 with a boost circuit 430 based on the first embodiment. It should be noted that the first charge pump circuit 130 in the second embodiment and the first charge pump circuit 330 in the third embodiment can also be replaced with a boost circuit 430.

[0240] Correspondingly, the power management control circuit in the switching power supply 400 is based on the power management control circuit of the switching power supply 100, except that the capacitor terminals C- and C+ are removed and the SW terminal is added.

[0241] In this embodiment, the boost circuit 430 includes an inductor L1, switching transistors Q1 and Q2, and a first control circuit 431. The inductor L1 is, for example, located outside the power management control circuit. The first terminal of the first inductor L1 is connected to the input terminal VIN to receive the first DC output voltage Vout1. The first terminal of the first switching transistor Q1 is, for example, grounded to the ground terminal GND via a resistor R8, and the second terminal of the first switching transistor Q1 is connected to the second terminal of the first inductor L1 via the SW terminal. The first terminal of the second switching transistor Q2 is connected to the second terminal of the first inductor L1 via the SW terminal, and the second terminal of the second switching transistor Q2 serves as the output terminal of the boost circuit, connected to the output terminal VOUT, and outputs the second DC output voltage Vout2. The first control circuit 431 is connected to the output terminal of the boost circuit, the control terminal of the first switching transistor Q1, and the control terminal of the second switching transistor Q2. It samples the output terminal of the boost circuit and generates drive signals for the first and second switching transistors based on the sampled signals and a reference voltage to control the boost circuit to convert the first DC output voltage into the second DC output voltage.

[0242] For example, the first control circuit 431 includes a second error amplifier EA2, a PWM comparator, and a control unit. The first input terminal of the second error amplifier EA2 samples the output terminal of the boost circuit through a voltage divider network composed of resistors R9 and R10, for example. The second input terminal of the second error amplifier EA2 receives a reference voltage. The PWM comparator is connected to the output terminal of the second error amplifier EA2 and to the first terminal of the first switching transistor Q1. The output terminal of the PWM comparator is connected to the control unit. The control unit generates drive signals for the first and second switching transistors based on the sampled signal and the reference voltage to control the boost circuit to convert the first DC output voltage into a second DC output voltage.

[0243] Furthermore, when the first switch Q1 is turned on, the first DC output voltage Vout1 charges and stores energy in the inductor L1. The charging current flows to ground through the first switch Q1 and resistor R8. During the freewheeling phase, the second switch Q2 is turned on. Resistors R9 and R10 are connected in series to divide the voltage, which is then connected to the error amplifier EA2. This error amplifier is compared with the reference signal Vref and output to the PWM comparator, thereby controlling the stability of the second DC output voltage VOUT.

[0244] Figure 6 This diagram illustrates the structure of a switching power supply according to the fifth embodiment of the present invention.

[0245] like Figure 6 As shown, the fifth embodiment of the switching power supply 500 replaces the boost circuit 430 with the boost circuit 530 based on the switching power supply 400.

[0246] The boost circuit 530 includes an inductor L1, a switching transistor Q1, a freewheeling diode D0, and a second control circuit 531. The inductor L1 is, for example, located outside the power management control circuit. The first terminal of the first inductor L1 is connected to the input terminal VIN to receive the first DC output voltage Vout1. The first terminal of the first switching transistor Q1 is grounded, for example, via a resistor R8 to the ground terminal GND, and the second terminal of the first switching transistor Q1 is connected to the second terminal of the first inductor L1 via the SW terminal. The first terminal of the freewheeling diode D0 is connected to the second terminal of the first inductor L1, and the second terminal of the freewheeling diode D0 serves as the output terminal of the boost circuit, connected to the output terminal VOUT, and outputs the second DC output voltage Vout2. The second control circuit 531 is connected to the output terminal of the boost circuit and the control terminal of the first switching transistor Q1. It samples the output terminal of the boost circuit and generates a drive signal for the first switching transistor based on the sampled signal and a reference voltage to control the boost circuit to convert the first DC output voltage into the second DC output voltage.

[0247] The difference between boost circuit 530 and boost circuit 430 is that the second switching transistor Q2 is replaced with a freewheeling diode D0. The difference between the second control circuit 531 and the first control circuit 431 is that the second control circuit 531 only provides the gate drive signal for the first switching transistor Q1. Generally, the freewheeling diode D0 is placed outside the power management control circuit or built into the power management control circuit chip.

[0248] Figure 7 This diagram illustrates the structure of a switching power supply according to the sixth embodiment of the present invention.

[0249] like Figure 7 As shown, the switching power supply 600 provided in the sixth embodiment integrates the low dropout linear regulator circuit 140 into the power management control circuit based on the first embodiment.

[0250] Correspondingly, the power management control circuit in the switching power supply 600 is based on the power management control circuit of the switching power supply 100, but the output terminal VOUT is replaced with output terminals VOUTH and VOUTL.

[0251] The low-dropout linear regulator circuit 140 is connected to its input terminal VIN, output terminal VOUTL, and ground. See the documentation for the low-dropout linear regulator circuit 140. Figure 15 The circuit structure shown is shown.

[0252] It should be noted that the implementation method of integrating a low-dropout linear regulator (LDO) into the power management control circuit provided in this embodiment can also be implemented in the second, third, fourth, and fifth embodiments.

[0253] Figure 8 This diagram illustrates the structure of a switching power supply according to the seventh embodiment of the present invention. Figure 17 This diagram shows a structural schematic of a second charge pump circuit provided by the present invention.

[0254] like Figure 8 As shown, in the seventh embodiment, the low-dropout linear regulator (LDO) in the sixth embodiment can be replaced with a step-down second charge pump circuit. The power management control circuit of the switching power supply 700 also integrates a second charge pump circuit 740 based on the power management control circuit of the switching power supply 100. Correspondingly, the power management control circuit in the switching power supply 600, based on the power management control circuit of the switching power supply 100, replaces the output terminal VOUT with output terminals VOUTH and VOUTL, and adds capacitor terminals C2+ and C2-.

[0255] It should be noted that the implementation method provided in this embodiment, which replaces the low dropout linear regulator (LDO) with a step-down second charge pump circuit and integrates it into the power management control circuit, can also be implemented in the second, third, fourth, and fifth embodiments.

[0256] The second charge pump circuit is, for example, as follows: Figure 17 The circuit shown is an example of this.

[0257] The peripheral components also include a fourth pump capacitor C14 and a fifth pump capacitor C15. The output terminal VOUTL is connected to the output terminal of the second charge pump circuit 740 to output a third DC output voltage Vout3, and is also grounded via capacitor C10. The input terminal of the second charge pump circuit 740 is connected to the input terminal VIN in the power management control circuit. The fourth pump capacitor C14 is connected between capacitor terminals C2+ and C2-. The fifth pump capacitor C15 is connected between the output terminal VOUTL and ground.

[0258] The third switch array of the second charge pump circuit 740 forms a charging circuit with the fourth pump capacitor C14 and the fifth pump capacitor C15, and also forms a discharging circuit with the fourth pump capacitor C14 and the fifth pump capacitor C15. In the charging circuit, the fourth pump capacitor C14 and the fifth pump capacitor C15 are connected in series between the first DC output voltage Vout1 and ground to charge the fourth pump capacitor C14 and the fifth pump capacitor C15. In the discharging circuit, the fourth pump capacitor C14 and the fifth pump capacitor C15 are connected in parallel between the third DC output voltage Vout3 and ground to output the third DC output voltage Vout3.

[0259] Exemplarily, the third switch array includes a ninth switch S9 through a twelfth switch S12. The ninth switch S9 is connected between the first DC output voltage Vout1 and the first terminal of the fourth pump capacitor C14. The tenth switch S10 is connected between the first terminal of the fourth pump capacitor C14 and the first terminal of the fifth pump capacitor C15. The eleventh switch S11 is connected between the second terminal of the fourth pump capacitor C14 and the first terminal of the fifth pump capacitor C15. The twelfth switch S12 is connected between the second terminal of the fourth pump capacitor C14 and ground. The first terminal of the fifth pump capacitor C15 is connected to the third DC output voltage Vout3, and the second terminal of the fifth pump capacitor C15 is grounded.

[0260] The ninth switch S9 and the eleventh switch S11 are turned on, forming a charging circuit with the fourth pump capacitor C14 and the fifth pump capacitor C15. The first DC output voltage Vout1 charges the fourth pump capacitor C14 and the fifth pump capacitor C15. Taking the capacitance values ​​of the fourth pump capacitor C14 and the fifth pump capacitor C15 as an example, the voltage across each capacitor is 0.5Vout1.

[0261] The tenth switch S10 and the twelfth switch S12 are turned on, forming a discharge circuit with the fourth pump capacitor C14 and the fifth pump capacitor C15. The fourth pump capacitor C14 and the fifth pump capacitor C15 are connected in parallel to provide the third DC output voltage Vout3.

[0262] Figure 9 This diagram illustrates the structure of a switching power supply according to the eighth embodiment of the present invention.

[0263] like Figure 9 As shown, the switching power supply 800 separates the drive control and power switching circuit 120, the first DC-DC conversion circuit 130, and the second DC-DC conversion circuit 140. The first DC-DC conversion circuit can be either a first charge pump circuit 130 or a boost circuit. The second DC-DC conversion circuit can be either a low-dropout linear regulator circuit 140 or a second charge pump circuit.

[0264] In the eighth embodiment, the primary and secondary sides of transformer T1 share a common ground.

[0265] Figure 10 This diagram illustrates the structure of a switching power supply according to the ninth embodiment of the present invention.

[0266] like Figure 10 As shown, the primary and secondary sides of the transformer T1 in the switching power supply 900 of the ninth embodiment are isolated. Based on the eighth embodiment, the switching power supply of the ninth embodiment adds some peripheral components.

[0267] For example, the eighth capacitor C8 is also connected to U1B. A sampling feedback network is also connected between the first DC output voltage Vout1 and the input terminal VIN of the first charge pump circuit 130. This sampling feedback network includes a third resistor R14, the input portion U1A of the optocoupler, the adjustable precision regulator D10, a fourth resistor R12, a fifth resistor R13 connected in series between the two, and a sixth resistor R11 and a sixth capacitor C20, which are part of a loop compensation network connecting the first connection node between the input portion U1A of the optocoupler and the adjustable precision regulator D10 and the second connection node between the fourth resistor R12 and the fifth resistor R13.

[0268] Figure 11 This diagram illustrates the structure of a switching power supply according to the tenth embodiment of the present invention. Figure 12 This diagram illustrates the structure of a switching power supply according to the eleventh embodiment of the present invention.

[0269] like Figure 11 As shown, the switching power supply 1000 replaces the flyback converter circuit with a buck circuit in the main circuit of the switching power supply 100 in the first embodiment.

[0270] like Figure 12 As shown, the switching power supply 1100 replaces the flyback converter circuit with a buck circuit in the main circuit of the switching power supply 400 in the fourth embodiment.

[0271] The buck circuit includes a rectifier bridge, a fifth diode D12, a second inductor L2, and a seventh capacitor C22. The input of the rectifier bridge receives the AC input voltage Vin, and the output of the rectifier bridge provides the rectified voltage, which is connected to the second terminal of the power switch via the DC input terminal DRAIN. The first terminal of the power switch is connected to the first terminal of the second inductor L2 and the cathode of the fifth diode D12. The seventh capacitor C22 is connected between the second terminal of the second inductor L2 and the anode of the fifth diode D12.

[0272] The anode of diode D11 receives the first DC output voltage Vout1, the cathode of diode D11 is connected to the power supply terminal VDD, and a capacitor C21 is connected between the cathode of diode D11 and the cathode of diode D12.

[0273] It should be noted that the flyback converter circuits in the third, fifth, sixth, seventh, and eighth embodiments of this application can also be replaced by buck circuits, for example.

[0274] The switching power supply disclosed herein integrates a DC-DC conversion circuit into the switching power supply, and uses the first DC output voltage generated in the switching power supply as the input DC voltage of the DC-DC conversion circuit. The DC-DC conversion circuit then generates at least one DC output voltage required by the low-power application circuit unit. This optimizes and improves the transformer design, peripheral components, and stability of the multi-output voltages in the multi-output switching power supply.

[0275] Furthermore, integrating the DC-DC conversion circuit with the drive control circuit simplifies the transformer design of the switching power supply, improves the stability of each output voltage, and reduces the cost of peripheral components in the system solution.

[0276] The embodiments of this utility model described above are examples of specific examples, and do not exhaustively describe all details, nor do they limit the utility model to only specific embodiments. Obviously, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to make good use of this utility model and its modifications. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A switching power supply, which converts an AC input voltage into a first DC output voltage under the control of a power management control circuit, characterized in that, The power management control circuit includes: Drive control circuit; A power switch, wherein the drive control circuit controls the power switch to be turned on and off; The first DC-DC converter circuit receives the first DC output voltage and converts the first DC output voltage into a second DC output voltage.

2. The switching power supply according to claim 1, characterized in that, Also includes: The second DC-DC converter circuit receives the first DC output voltage and converts the first DC output voltage into a third DC output voltage.

3. The switching power supply according to claim 1 or 2, characterized in that, The first DC-DC conversion circuit is a first charge pump circuit.

4. The switching power supply according to claim 1 or 2, characterized in that, The first DC-DC converter circuit is a boost circuit.

5. The switching power supply according to claim 3, characterized in that, The first charge pump circuit includes: The first pump capacitor and the second pump capacitor are connected in series; A first switch array forms a charging circuit with the first pump capacitor and the second pump capacitor, and a discharging circuit with the first pump capacitor. In the charging circuit, the first pump capacitor and the second pump capacitor are connected in series between the first DC output voltage and ground to charge the first pump capacitor and the second pump capacitor. In the discharging circuit, the first pump capacitor is connected between the first DC output voltage and the second DC output voltage to superimpose the voltage on the first pump capacitor onto the first DC output voltage, thereby generating the second DC output voltage.

6. The switching power supply according to claim 3, characterized in that, The first charge pump circuit includes: Third pump capacitor; The second switch array forms a charging circuit and a discharging circuit with the third pump capacitor. The charging circuit receives the first DC output voltage to charge the third pump capacitor, and the discharging circuit discharges the third pump capacitor to superimpose the voltage on the third pump capacitor onto the first DC output voltage, thereby generating the second DC output voltage. A voltage regulator, connected to the second switch array, generates a first error amplification signal based on a voltage signal characterizing the second DC output voltage and a first reference voltage; A logic control unit, connected to the voltage regulator and the second switch array, generates a control signal based on the first error amplification signal to control the conduction of the charging circuit or the discharging circuit.

7. The switching power supply according to claim 5, characterized in that, The first switch array includes: A first switch is connected between the first DC output voltage and the first terminal of the second pump capacitor; The second switch is connected between the second terminal of the second pump capacitor and the second DC output voltage. The third switch is connected between the second terminal of the first pump capacitor and ground; A fourth switch is connected between the second terminal of the first pump capacitor and the first DC output voltage. The second terminal of the second pump capacitor is connected to the first terminal of the first pump capacitor. The first switch is turned on, the third switch is turned on, and together with the first pump capacitor and the second pump capacitor, they form the charging circuit; the fourth switch is turned on, the second switch is turned on, and together with the first pump capacitor, they form the discharging circuit.

8. The switching power supply according to claim 6, characterized in that, The second switch array includes: The fifth switch is connected between the first DC output voltage and the first terminal of the third pump capacitor; The sixth switch is connected between the second terminal of the third pump capacitor and ground; The seventh switch is connected between the first terminal of the third pump capacitor and the second DC output voltage; The eighth switch is connected between the first DC output voltage and the second terminal of the third pump capacitor. The fifth switch is turned on, the sixth switch is turned on, and together with the third pump capacitor, they form the charging circuit; the eighth switch is turned on, the seventh switch is turned on, and together with the third pump capacitor, they form the discharging circuit.

9. The switching power supply according to claim 3, characterized in that, The first charge pump circuit and the drive control circuit are integrated in the same chip, and the pump capacitor in the first charge pump circuit is located outside the chip.

10. The switching power supply according to claim 3, characterized in that, The power switch, the first charge pump circuit, and the drive control circuit are integrated in the same chip, and the pump capacitor in the first charge pump circuit is placed outside the chip.

11. The switching power supply according to claim 4, characterized in that, The boost circuit includes: The first inductor receives the first DC output voltage at its first terminal. The first switching transistor has a first terminal grounded through a sampling resistor, and the second terminal of the first switching transistor is connected to the second terminal of the first inductor. The second switching transistor has its first terminal connected to the second terminal of the first inductor, and its second terminal serves as the output terminal of the boost circuit to output the second DC output voltage. A first control circuit is connected to the output terminal of the boost circuit, the control terminal of the first switch, and the control terminal of the second switch. It samples the output terminal of the boost circuit and generates an error amplification signal based on the sampled signal and a reference voltage. The error amplification signal is compared with the current sampling signal of the first switch to generate a drive signal for the first switch and a drive signal for the second switch to control the boost circuit to convert the first DC output voltage into the second DC output voltage.

12. The switching power supply according to claim 4, characterized in that, The boost circuit includes: The first inductor receives the first DC output voltage at its first terminal. The first switching transistor has a first terminal grounded through a sampling resistor, and the second terminal of the first switching transistor is connected to the second terminal of the first inductor. A freewheeling diode, wherein the first end of the freewheeling diode is connected to the second end of the first inductor, and the second end of the freewheeling diode serves as the output terminal of the boost circuit to output the second DC output voltage; The second control circuit is connected to the output terminal of the boost circuit and the control terminal of the first switching transistor. It samples the output terminal of the boost circuit and generates an error amplification signal based on the sampled signal and the reference voltage. The error amplification signal is compared with the current sampling signal of the first switching transistor to generate a drive signal for the first switching transistor to control the boost circuit to convert the first DC output voltage into the second DC output voltage.

13. The switching power supply according to claim 4, characterized in that, The boost circuit and the drive control circuit are integrated in the same chip. The first inductor in the boost circuit is placed outside the chip, or the first inductor and the freewheeling diode in the boost circuit are placed outside the chip.

14. The switching power supply according to claim 4, characterized in that, The power switch is integrated with the boost circuit and the drive control circuit in the same chip. The first inductor in the boost circuit is placed outside the chip, or the first inductor and the freewheeling diode in the boost circuit are placed outside the chip.

15. The switching power supply according to claim 2, characterized in that, The second DC-DC converter circuit is a low-dropout linear regulator circuit.

16. The switching power supply according to claim 2, characterized in that, The second DC-DC conversion circuit is a second charge pump circuit.

17. The switching power supply according to claim 15, characterized in that, The low-dropout linear regulator circuit and the drive control circuit are integrated in the same chip.

18. The switching power supply according to claim 15, characterized in that, The low-dropout linear regulator circuit is integrated with the drive control circuit in the same chip, and is also integrated with at least one of the power switch and the first DC-DC conversion circuit in the same chip.

19. The switching power supply according to claim 16, characterized in that, The second charge pump circuit is integrated with the drive control circuit in the same chip, and the pump capacitor in the second charge pump circuit is located outside the chip.

20. The switching power supply according to claim 16, characterized in that, The second charge pump circuit is integrated with the drive control circuit in the same chip, and is also integrated with at least one of the power switch and the first DC-DC conversion circuit in the same chip. The pump capacitor in the second charge pump circuit is located outside the chip.

21. The switching power supply according to claim 15, characterized in that, The low-dropout linear regulator circuit includes: The third switching transistor is connected between the first DC output voltage and the third DC output voltage; The fourth switch is connected between the first DC output voltage and the control terminal of the third switch; The fifth switch is connected between the first DC output voltage and the control terminal of the fourth switch; A first error amplifier receives a voltage signal characterizing the third DC output voltage and a reference voltage, and outputs a second error amplification signal characterizing the third DC output voltage and the reference voltage, which is then provided to the control terminal of the fifth switching transistor; and A DC constant current source is connected between the control terminal of the fifth switching transistor and ground.

22. The switching power supply according to claim 16, characterized in that, The second charge pump circuit includes: Fourth pump capacitor, fifth pump capacitor; The third switch array forms a charging circuit with the fourth and fifth pump capacitors, and a discharging circuit with the fourth and fifth pump capacitors. In the charging circuit, the fourth and fifth pump capacitors are connected in series between the first DC output voltage and ground to charge the fourth and fifth pump capacitors. In the discharging circuit, the fourth and fifth pump capacitors are connected in parallel between the third DC output voltage and ground to output the third DC output voltage.

23. The switching power supply according to claim 22, characterized in that, The third switch array includes: The ninth switch is connected between the first DC output voltage and the first terminal of the fourth pump capacitor; The tenth switch is connected between the first terminal of the fourth pump capacitor and the first terminal of the fifth pump capacitor. The eleventh switch is connected between the second terminal of the fourth pump capacitor and the first terminal of the fifth pump capacitor. The twelfth switch is connected between the second terminal of the fourth pump capacitor and ground. The first terminal of the fifth pump capacitor is connected to the third DC output voltage, and the second terminal of the fifth pump capacitor is grounded. The ninth switch and the eleventh switch are turned on, forming the charging circuit with the fourth pump capacitor and the fifth pump capacitor. The tenth switch and the twelfth switch are turned on, forming the discharging circuit with the fourth pump capacitor and the fifth pump capacitor.

24. The switching power supply according to claim 1, characterized in that, Also includes: A flyback converter or buck converter, under the control of a power management control circuit, converts the AC input voltage into a first DC output voltage.

25. The switching power supply according to claim 24, characterized in that, The flyback converter circuit includes: The rectifier unit rectifies the AC input voltage and outputs a rectified voltage; The transformer includes an input winding and an output winding. The first end of the input winding is connected to the rectifier unit to receive the rectified voltage, and the second end of the input winding is connected to the second end of the power switch. The output winding outputs the first DC output voltage after rectification and filtering. A first diode, the anode of which is connected to the first end of the output winding; A first capacitor is connected between the second end of the output winding and the cathode of the first diode.

26. The switching power supply according to claim 25, characterized in that, The flyback converter circuit also includes: A first resistor, the first end of which is connected to the first end of the input winding; A second capacitor, the first end of which is connected to the first end of the input winding; The second diode has its anode connected to the second end of the input winding, and its cathode connected to the second end of the first resistor and the second end of the second capacitor. The second resistor and the third capacitor are connected in series between the anode and the cathode of the first diode.

27. The switching power supply according to claim 25, characterized in that, The transformer further includes an auxiliary winding, which, along with the input winding, is located on the primary side of the transformer. The output winding is located on the secondary side of the transformer. The auxiliary winding provides a power supply voltage to the drive control circuit. The flyback converter circuit further includes: A fourth diode, wherein the anode of the fourth diode is connected to the second end of the auxiliary winding; The fifth capacitor is connected between the first end of the auxiliary winding and the cathode of the fourth diode, and the cathode of the fourth diode also provides the power supply voltage.

28. The switching power supply according to claim 27, characterized in that, Also includes: The third resistor, the input section of the optocoupler, the adjustable precision regulator, the fourth resistor, and the fifth resistor are connected in series between the first DC output voltage and the first charge pump circuit. as well as The first connection node is connected in series between the input section of the optocoupler and the adjustable precision regulator, and the sixth resistor and sixth capacitor are connected in series between the second connection node between the fourth resistor and the fifth resistor.

29. The switching power supply according to claim 1, characterized in that, The drive control circuit generates the gate drive signal of the power switch based on the supply voltage and the voltage signal characterizing the first DC output voltage, wherein the supply voltage is provided by the second DC output voltage output by the first DC conversion circuit.

30. The switching power supply according to claim 24, characterized in that, The buck circuit includes: A rectifier bridge, the input of which receives an AC input voltage, and the output of which provides a rectified voltage and is connected to the second terminal of the power switch; The second inductor has its first end connected to the first end of the power switch and its second end connected to the first DC output voltage. The fifth diode, wherein the cathode of the fifth diode is connected to the first terminal of the second inductor; The seventh capacitor has its first terminal connected to the second terminal of the second inductor, and its second terminal connected to the anode of the fifth diode and grounded.

31. The switching power supply according to claim 1, characterized in that, The power management control circuit includes a DC input terminal and a sampling terminal. The second terminal of the power switch is connected to the DC input terminal. The first terminal of the power switch is grounded via the sampling terminal and a sampling resistor. The control terminal of the power switch receives the gate drive signal generated by the drive control circuit.

32. The switching power supply according to claim 1, characterized in that, The drive control circuit, the power switch, the first DC-DC conversion circuit, and the second DC-DC conversion circuit are integrated into the same chip.

33. A power management control circuit for a switching power supply, characterized in that, include: Drive control circuit; A power switch, wherein the drive control circuit controls the power switch to be turned on and off; The first DC-DC converter circuit receives the first DC output voltage and converts the first DC output voltage into a second DC output voltage.

34. The power management control circuit according to claim 33, characterized in that, Also includes: The second DC-DC converter circuit receives the first DC output voltage and converts the first DC output voltage into a third DC output voltage.

35. The power management control circuit according to claim 33 or 34, characterized in that, The first DC-DC conversion circuit is a first charge pump circuit.

36. The power management control circuit according to claim 33 or 34, characterized in that, The first DC-DC converter circuit is a boost circuit.

37. The power management control circuit according to claim 35, characterized in that, The first charge pump circuit includes: The first pump capacitor and the second pump capacitor are connected in series; A first switch array forms a charging circuit with the first pump capacitor and the second pump capacitor, and a discharging circuit with the first pump capacitor. In the charging circuit, the first pump capacitor and the second pump capacitor are connected in series between the first DC output voltage and ground to charge the first pump capacitor and the second pump capacitor. In the discharging circuit, the first pump capacitor is connected between the first DC output voltage and the second DC output voltage to superimpose the voltage on the first pump capacitor onto the first DC output voltage, thereby generating the second DC output voltage.

38. The power management control circuit according to claim 35, characterized in that, The first charge pump circuit includes: Third pump capacitor; The second switch array forms a charging circuit and a discharging circuit with the third pump capacitor. The charging circuit receives the first DC output voltage to charge the third pump capacitor, and the discharging circuit discharges the third pump capacitor to superimpose the voltage on the third pump capacitor onto the first DC output voltage, thereby generating the second DC output voltage. A voltage regulator, connected to the second switch array, generates a first error amplification signal based on a voltage signal characterizing the second DC output voltage and a first reference voltage; A logic control unit, connected to the voltage regulator and the second switch array, generates a control signal based on the first error amplification signal to control the conduction of the charging circuit or the discharging circuit.

39. The power management control circuit according to claim 37, characterized in that, The first switch array includes: A first switch is connected between the first DC output voltage and the first terminal of the second pump capacitor; The second switch is connected between the second terminal of the second pump capacitor and the second DC output voltage. The third switch is connected between the second terminal of the first pump capacitor and ground; A fourth switch is connected between the second terminal of the first pump capacitor and the first DC output voltage. The second terminal of the second pump capacitor is connected to the first terminal of the first pump capacitor. The first switch is turned on, the third switch is turned on, and together with the first pump capacitor and the second pump capacitor, they form the charging circuit; the fourth switch is turned on, the second switch is turned on, and together with the first pump capacitor, they form the discharging circuit.

40. The power management control circuit according to claim 38, characterized in that, The second switch array includes: The fifth switch is connected between the first DC output voltage and the first terminal of the third pump capacitor; The sixth switch is connected between the second terminal of the third pump capacitor and ground; The seventh switch is connected between the first terminal of the third pump capacitor and the second DC output voltage; The eighth switch is connected between the first DC output voltage and the second terminal of the third pump capacitor. The fifth switch is turned on, the sixth switch is turned on, and together with the third pump capacitor, they form the charging circuit; the eighth switch is turned on, the seventh switch is turned on, and together with the third pump capacitor, they form the discharging circuit.

41. The power management control circuit according to claim 35, characterized in that, The first charge pump circuit and the drive control circuit are integrated in the same chip, and the pump capacitor in the first charge pump circuit is located outside the chip.

42. The power management control circuit according to claim 35, characterized in that, The power switch, the first charge pump circuit, and the drive control circuit are integrated in the same chip, and the pump capacitor in the first charge pump circuit is placed outside the chip.

43. The power management control circuit according to claim 36, characterized in that, The boost circuit includes: The first inductor receives the first DC output voltage at its first terminal. The first switching transistor has a first terminal grounded through a sampling resistor, and the second terminal of the first switching transistor is connected to the second terminal of the first inductor. The second switching transistor has its first terminal connected to the second terminal of the first inductor, and its second terminal serves as the output terminal of the boost circuit to output the second DC output voltage. A first control circuit is connected to the output terminal of the boost circuit, the control terminal of the first switch, and the control terminal of the second switch. It samples the output terminal of the boost circuit and generates an error amplification signal based on the sampled signal and a reference voltage. The error amplification signal is compared with the current sampling signal of the first switch to generate a drive signal for the first switch and a drive signal for the second switch to control the boost circuit to convert the first DC output voltage into the second DC output voltage.

44. The power management control circuit according to claim 36, characterized in that, The boost circuit includes: The first inductor receives the first DC output voltage at its first terminal. The first switching transistor has a first terminal grounded through a sampling resistor, and the second terminal of the first switching transistor is connected to the second terminal of the first inductor. A freewheeling diode, wherein the first end of the freewheeling diode is connected to the second end of the first inductor, and the second end of the freewheeling diode serves as the output terminal of the boost circuit to output the second DC output voltage; The second control circuit is connected to the output terminal of the boost circuit and the control terminal of the first switching transistor. It samples the output terminal of the boost circuit and generates an error amplification signal based on the sampled signal and the reference voltage. The error amplification signal is compared with the current sampling signal of the first switching transistor to generate a drive signal for the first switching transistor to control the boost circuit to convert the first DC output voltage into the second DC output voltage.

45. The power management control circuit according to claim 36, characterized in that, The boost circuit and the drive control circuit are integrated in the same chip. The first inductor in the boost circuit is placed outside the chip, or the first inductor and the freewheeling diode in the boost circuit are placed outside the chip.

46. ​​The power management control circuit according to claim 36, characterized in that, The power switch is integrated with the boost circuit and the drive control circuit in the same chip. The first inductor in the boost circuit is placed outside the chip, or the first inductor and the freewheeling diode in the boost circuit are placed outside the chip.

47. The power management control circuit according to claim 34, characterized in that, The second DC-DC converter circuit is a low-dropout linear regulator circuit.

48. The power management control circuit according to claim 34, characterized in that, The second DC-DC conversion circuit is a second charge pump circuit.

49. The power management control circuit according to claim 47, characterized in that, The low-dropout linear regulator circuit and the drive control circuit are integrated in the same chip.

50. The power management control circuit according to claim 47, characterized in that, The low-dropout linear regulator circuit is integrated with the drive control circuit in the same chip, and is also integrated with at least one of the power switch and the first DC-DC conversion circuit in the same chip.

51. The power management control circuit according to claim 48, characterized in that, The second charge pump circuit is integrated with the drive control circuit in the same chip, and the pump capacitor in the second charge pump circuit is located outside the chip.

52. The power management control circuit according to claim 48, characterized in that, The second charge pump circuit is integrated with the drive control circuit in the same chip, and is also integrated with at least one of the power switch and the first DC-DC conversion circuit in the same chip. The pump capacitor in the second charge pump circuit is located outside the chip.

53. The power management control circuit according to claim 47, characterized in that, The low-dropout linear regulator circuit includes: The third switching transistor is connected between the first DC output voltage and the third DC output voltage; The fourth switch is connected between the first DC output voltage and the control terminal of the third switch; The fifth switch is connected between the first DC output voltage and the control terminal of the fourth switch; A first error amplifier receives a voltage signal characterizing the third DC output voltage and a reference voltage, and outputs a second error amplification signal characterizing the third DC output voltage and the reference voltage, which is then provided to the control terminal of the fifth switching transistor; and A DC constant current source is connected between the control terminal of the fifth switching transistor and ground.

54. The power management control circuit according to claim 48, characterized in that, The second charge pump circuit includes: Fourth pump capacitor, fifth pump capacitor; The third switch array forms a charging circuit with the fourth and fifth pump capacitors, and a discharging circuit with the fourth and fifth pump capacitors. In the charging circuit, the fourth and fifth pump capacitors are connected in series between the first DC output voltage and ground to charge the fourth and fifth pump capacitors. In the discharging circuit, the fourth and fifth pump capacitors are connected in parallel between the third DC output voltage and ground to output the third DC output voltage.

55. The power management control circuit according to claim 54, characterized in that, The third switch array includes: The ninth switch is connected between the first DC output voltage and the first terminal of the fourth pump capacitor; The tenth switch is connected between the first terminal of the fourth pump capacitor and the first terminal of the fifth pump capacitor. The eleventh switch is connected between the second terminal of the fourth pump capacitor and the first terminal of the fifth pump capacitor. The twelfth switch is connected between the second terminal of the fourth pump capacitor and ground. The first terminal of the fifth pump capacitor is connected to the third DC output voltage, and the second terminal of the fifth pump capacitor is grounded. The ninth switch and the eleventh switch are turned on, forming the charging circuit with the fourth pump capacitor and the fifth pump capacitor. The tenth switch and the twelfth switch are turned on, forming the discharging circuit with the fourth pump capacitor and the fifth pump capacitor.

56. The power management control circuit according to claim 33, characterized in that, The drive control circuit generates the gate drive signal of the power switch based on the supply voltage and the voltage signal characterizing the first DC output voltage, wherein the supply voltage is provided by the second DC output voltage output by the first DC conversion circuit.

57. The power management control circuit according to claim 33, characterized in that, The power management control circuit includes a DC input terminal and a sampling terminal. The second terminal of the power switch is connected to the DC input terminal. The first terminal of the power switch is grounded via the sampling terminal and a sampling resistor. The control terminal of the power switch receives the gate drive signal generated by the drive control circuit.

58. The power management control circuit according to claim 33, characterized in that, The drive control circuit, the power switch, the first DC-DC conversion circuit, and the second DC-DC conversion circuit are integrated into the same chip.

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