CN219918469U - Power supply circuit with sampling function - Google Patents

Abstract

The utility model discloses a power supply circuit with a sampling function, which includes: a charging circuit, the input end is connected to an external power supply, the output end is connected to the input end of the sampling circuit and the input end of the switching circuit; the sampling circuit, the output end is connected to the main control Circuit connection; switch circuit, the output terminal is connected to the input terminal of the discharge circuit; the discharge circuit, the output terminal is connected to the first load and the second load. This application outputs the second voltage to the main control circuit through the sampling circuit, so that the power supply circuit has a sampling function, which facilitates sampling of the second voltage output by the charging circuit and outputs it to the main control circuit, thereby improving the efficiency of the power supply circuit.

Description

Power supply circuit with sampling function

Technical field

The utility model relates to the technical field of power supply circuits with sampling functions, and in particular to a power supply circuit with sampling functions.

Background technique

The power supply circuit is a circuit used to provide different power supply voltages to the load. The power supply circuit contains a charging circuit and a discharging circuit. The voltage output by the charging circuit is directly related to whether the voltage output by the discharging circuit can meet the needs of the load. Existing The power supply circuit in the technology only has charging and discharging functions and cannot sample the voltage output by the charging circuit, which makes the power supply circuit have a single function and reduces the efficiency of the power supply circuit.

Utility model content

Based on this, it is necessary to propose a power supply circuit with sampling function to address the above problems.

A power supply circuit with sampling function, including:

A charging circuit, the input end is connected to the external power supply, the output end is connected to the input end of the sampling circuit and the input end of the switching circuit, for receiving the first voltage provided by the external power supply and storing electrical energy; and The voltage is converted into the second voltage and then output to the sampling circuit and the switching circuit;

The output terminal of the sampling circuit is connected to the main control circuit, and is used to obtain the second voltage output by the charging circuit, and output the second voltage to the main control circuit;

The output terminal of the switch circuit is connected to the input terminal of the discharge circuit, and is used to control the conduction or disconnection of the path between the charging circuit and the discharge circuit;

The output terminal of the discharge circuit is connected to the first load and the second load, and is used to receive the second voltage, convert the second voltage into a fourth voltage and a fifth voltage, and output them to the first voltage. load and the second load.

In one embodiment, the power supply circuit with sampling function further includes:

An amplifying circuit has an input terminal connected to the output terminal of the charging circuit and an output terminal connected to the input terminal of the switching circuit, for amplifying the second voltage output by the charging circuit and outputting it to the switching circuit.

In one embodiment, the discharge circuit includes:

The first voltage conversion circuit has an input terminal connected to the output terminal of the charging circuit and an output terminal connected to the input terminal of the second voltage conversion circuit and the input terminal of the third voltage conversion circuit for converting the second voltage into The third voltage is then output to the second voltage conversion circuit and the third voltage conversion circuit;

The second voltage conversion circuit has an output terminal connected to the first load and is used to convert the third voltage into a fourth voltage and then output it to the first load;

The output terminal of the third voltage conversion circuit is connected to the second load, and is used to convert the third voltage into a fifth voltage and then output it to the second load.

In one embodiment, the charging circuit includes: a battery charging tube, a first MOS tube, a first diode, a second diode, a first inductor and a first resistor;

The switch circuit includes: a switch;

The power supply end of the battery charging tube is connected to the external power supply;

The driving end of the battery charging tube is connected to the gate of the first MOS tube;

The source of the first MOS tube is connected to the external power supply, the drain of the first MOS tube is connected to the anode of the first diode, and the cathode of the first diode is connected to the third diode. One end of an inductor is connected, the other end of the first inductor is connected to the current detection end of the battery charging tube and one end of the first resistor, the other end of the first resistor is connected to one end of the switch and the The input end of the sampling circuit is connected, and the other end of the switch is connected to the input end of the discharge circuit.

In one embodiment, the sampling circuit includes: a third diode, a fourth diode, a second resistor, a third resistor, a fourth resistor, a first capacitor and a second capacitor;

The cathode of the third diode is connected to the output end of the charging circuit, and the anode of the third diode is grounded;

The cathode of the fourth diode is connected to the cathode of the third diode, and the anode of the fourth diode is grounded;

One end of the second resistor is connected to the cathode of the third diode, and the other end is connected to the cathode of the fourth diode;

One end of the third resistor is connected to the cathode of the fourth diode, the other end is connected to the input end of the main control circuit and one end of the fourth resistor, and the other end of the fourth resistor is connected to ground;

One end of the first capacitor is connected to an end of the second resistor close to the third diode, and the other end of the first capacitor is connected to ground;

One end of the second capacitor is connected to an end of the second resistor close to the fourth diode, and the other end of the second capacitor is connected to ground.

In one embodiment, the first voltage conversion circuit includes: a third capacitor, a fourth capacitor, a fifth capacitor, a first voltage regulator, a sixth capacitor, a seventh capacitor, a fifth resistor, and a fifth diode. and a second inductor;

One end of the third capacitor is connected to the output end of the charging circuit and the power supply end of the first voltage regulator, and the other end of the third capacitor is connected to ground;

The fourth capacitor and the fifth capacitor are both connected in parallel with the third capacitor;

The high-side power end of the first voltage regulator is connected to one end of the second inductor and the cathode of the fifth diode;

The frequency compensation end of the first voltage regulator is connected to one end of the sixth capacitor, the other end of the sixth capacitor is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to ground; One end of the seventh capacitor is connected to the frequency compensation end of the first voltage regulator, and the other end is connected to ground;

The anode of the fifth diode is connected to the ground terminal of the first voltage regulator and grounded;

The other end of the second inductor is connected to the input terminal of the second voltage conversion circuit and the input terminal of the third voltage conversion circuit.

In one embodiment, the first voltage conversion circuit further includes: an eighth capacitor and a ninth capacitor;

One end of the eighth capacitor is connected to the other end of the second inductor, and the other end of the eighth capacitor is connected to ground;

The ninth capacitor is connected in parallel with the eighth capacitor.

In one embodiment, the second voltage conversion circuit includes: a second voltage regulator, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor and a fourteenth capacitor;

The power supply end of the second voltage regulator is connected to the other end of the second inductor;

The ground terminal of the second voltage regulator is connected to ground;

The output end of the second voltage regulator is connected to the first load;

One end of the tenth capacitor is connected to the other end of the second inductor, and the other end is grounded;

The eleventh capacitor is connected in parallel with the tenth capacitor;

One end of the twelfth capacitor is connected to the output end of the second voltage regulator, and the other end is connected to ground;

The thirteenth capacitor and the fourteenth capacitor are both connected in parallel with the twelfth capacitor.

In one embodiment, the third voltage conversion circuit includes: a boost converter, a fourth inductor, a sixth diode, a fifteenth capacitor, a sixteenth capacitor, a sixth resistor and a seventh resistor;

The power supply end of the boost converter is connected to the other end of the second inductor and one end of the fourth inductor, and the other end of the fourth inductor is connected to the switching end of the boost converter and the third inductor. The anodes of the six diodes are connected, and the cathode of the sixth diode is connected to the second load and one end of the fifteenth capacitor;

The other end of the fifteenth capacitor is connected to the feedback end of the boost converter;

One end of the sixth resistor is connected to the cathode of the sixth diode, and the other end of the sixth resistor is connected to the feedback end of the boost converter;

One end of the seventh resistor is connected to the feedback end of the boost converter, and the other end of the seventh resistor is connected to ground;

One end of the sixteenth capacitor is connected to the cathode of the sixth diode, and the other end of the sixteenth capacitor is connected to ground.

In one embodiment, the amplification circuit includes: a second MOS transistor and a seventh diode;

The drain of the second MOS transistor is connected to the output end of the charging circuit and the anode of the seventh diode;

The cathode of the seventh diode is connected to the source of the second MOS tube and the input end of the switch circuit;

The gate of the second MOS transistor is grounded.

Implementing the embodiments of the present invention will have the following beneficial effects:

This application obtains the first voltage provided by the external power supply through the charging circuit, stores the electric energy, and at the same time converts the first voltage into the second voltage and outputs it to the sampling circuit and the switching circuit; the switching circuit controls the charging circuit and the discharging circuit to be on or off. Open; the discharge circuit converts the second voltage into the fourth voltage and the fifth voltage, and outputs them to the first load and the second load; at the same time, the sampling circuit outputs the second voltage to the main control circuit; so that the power supply circuit has the sampling function , it is convenient to sample the second voltage output by the charging circuit and output it to the main control circuit, which improves the efficiency of the power supply circuit.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description These are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

in:

Figure 1 is a structural block diagram of a power supply circuit with a sampling function in one embodiment;

Figure 2 is a structural block diagram of a power supply circuit with a sampling function in another embodiment;

Figure 3 is a circuit diagram of a charging circuit in one embodiment;

Figure 4 is a circuit diagram of a switching circuit in an embodiment;

Figure 5 is a circuit diagram of a sampling circuit in an embodiment;

Figure 6 is a circuit diagram of a first voltage conversion circuit in an embodiment;

Figure 7 is a circuit diagram of a second voltage conversion circuit in an embodiment;

Figure 8 is a circuit diagram of a third voltage conversion circuit in an embodiment;

Figure 9 is a circuit diagram of an amplifier circuit in one embodiment.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only part of the embodiments of the present utility model, not all implementations. example. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present utility model.

The power supply circuit is a circuit used to provide different power supply voltages to the load. The power supply circuit contains a charging circuit and a discharging circuit. The voltage output by the charging circuit is directly related to whether the voltage output by the discharging circuit can meet the needs of the load. Existing The power supply circuit in the technology only has charging and discharging functions and cannot sample the voltage output by the charging circuit, which makes the power supply circuit have a single function and reduces the efficiency of the power supply circuit. In order to solve the above technical problems, the present application provides a power supply circuit with a sampling function, as shown in Figures 1 and 2, including: a charging circuit 10, a sampling circuit 20, a switching circuit 30, a discharging circuit 40 and an amplifying circuit 50; wherein , the input end of the charging circuit 10 is connected to an external power supply, and the output end is connected to the input end of the sampling circuit 20 and the input end of the switching circuit 30, for receiving the first voltage provided by the external power supply and storing electrical energy; and convert the first voltage into a second voltage and output it to the sampling circuit 20 and the switch circuit 30; the output end of the sampling circuit 20 is connected to the main control circuit for obtaining the output of the charging circuit 10 the second voltage, and outputs the second voltage to the main control circuit; the output end of the switch circuit 30 is connected to the input end of the discharge circuit 40 for controlling the charging circuit 10 and the The path between the discharge circuit 40 is turned on or off; the output end of the discharge circuit 40 is connected to the first load and the second load for receiving the second voltage and converting the second voltage into The fourth voltage and the fifth voltage are output to the first load and the second load. The input terminal of the amplifier circuit 50 is connected to the output terminal of the charging circuit 10, and the output terminal is connected to the input terminal of the switch circuit 30, for amplifying the second voltage output by the charging circuit 10 and then outputting it to The switch circuit 30. This application obtains the first voltage provided by the external power supply through the charging circuit, stores the electric energy, and at the same time converts the first voltage into the second voltage and outputs it to the sampling circuit and the switching circuit; the switching circuit controls the charging circuit and the discharging circuit to be on or off. Open; the discharge circuit converts the second voltage into the fourth voltage and the fifth voltage, and outputs them to the first load and the second load; at the same time, the sampling circuit outputs the second voltage to the main control circuit; so that the power supply circuit has the sampling function , it is convenient to sample the second voltage output by the charging circuit and output it to the main control circuit, which improves the efficiency of the power supply circuit.

In one embodiment, as shown in Figure 2, the discharge circuit 40 includes: a first voltage conversion circuit 401, a second voltage conversion circuit 402 and a third voltage conversion circuit 403; wherein the first voltage conversion circuit 401 The input terminal is connected to the output terminal of the charging circuit 10, and the output terminal is connected to the input terminal of the second voltage conversion circuit 402 and the input terminal of the third voltage conversion circuit 403 for converting the second voltage into a third voltage. The voltage is then output to the second voltage conversion circuit 402 and the third voltage conversion circuit 403; the output end of the second voltage conversion circuit 402 is connected to the first load for converting the third voltage to the fourth voltage and then output it to the first load; the output end of the third voltage conversion circuit 403 is connected to the second load for converting the third voltage to a fifth voltage and then outputs it to the Second load.

In one embodiment, as shown in Figure 3, the charging circuit 10 includes: battery charging tube U9, first MOS tube Q6, first diode D8, second diode D9, first inductor L2 and A resistor R39; as shown in Figure 4, the switch circuit 30 includes: a switch TS1; wherein the power supply terminal VCC of the battery charging tube U9 is connected to the external power supply; the driving terminal DRV of the battery charging tube U9 is connected to The gate of the first MOS tube Q6 is connected; the source of the first MOS tube Q6 is connected to the external power supply, and the drain of the first MOS tube Q6 is connected to the anode of the first diode D8. connection, the cathode of the first diode D8 is connected to one end of the first inductor L2, and the other end of the first inductor L2 is connected to the current detection terminal CSP of the battery charging tube U9 and the first resistor One end of R39 is connected, the other end of the first resistor R39 is connected to one end of the switch TS1 and the input end of the sampling circuit 20 , and the other end of the switch TS1 is connected to the input end of the discharge circuit 40 .

In one embodiment, as shown in Figure 5, the sampling circuit 20 includes: a third diode D4, a fourth diode D5, a second resistor R28, a third resistor R29, a fourth resistor R31, a first Capacitor C33 and second capacitor C34; wherein, the cathode of the third diode D4 is connected to the output end of the charging circuit 10, and the anode of the third diode D4 is grounded; the fourth diode The cathode of D5 is connected to the cathode of the third diode D4, and the anode of the fourth diode D5 is grounded; one end of the second resistor R28 is connected to the cathode of the third diode D4, and the other end of the second resistor R28 is connected to the cathode of the third diode D4. One end is connected to the cathode of the fourth diode D5; one end of the third resistor R29 is connected to the cathode of the fourth diode D5, and the other end is connected to the input end of the main control circuit and the third resistor R29. One end of the four resistors R31 is connected, and the other end of the fourth resistor R31 is connected to ground; one end of the first capacitor C33 is connected to an end of the second resistor R28 close to the third diode D4, and the first capacitor C33 The other end of the capacitor C33 is grounded; one end of the second capacitor C34 is connected to an end of the second resistor R28 close to the fourth diode D5, and the other end of the second capacitor C34 is grounded.

In one embodiment, as shown in Figure 6, the first voltage conversion circuit 401 includes: a third capacitor C75, a fourth capacitor C70, a fifth capacitor C71, a first voltage regulator U11, a sixth capacitor C82, Seven capacitor C83, fifth resistor R55, fifth diode D10 and second inductor L3; wherein, one end of the third capacitor C75 is connected to the output end of the charging circuit 501 and the first voltage regulator U11 The power supply terminal VIN is connected, and the other end of the third capacitor C75 is connected to ground;

The fourth capacitor C70 and the fifth capacitor C71 are both connected in parallel with the third capacitor C75; the high-side power terminal PH of the first voltage regulator U11 and one end of the second inductor L3 and the fifth second The cathode of the transistor D10 is connected; the frequency compensation terminal COMP of the first voltage regulator U11 is connected to one end of the sixth capacitor C82, and the other end of the sixth capacitor C82 is connected to one end of the fifth resistor R55. , the other end of the fifth resistor R55 is grounded; one end of the seventh capacitor C83 is connected to the frequency compensation terminal COMP of the first voltage regulator U11, and the other end is grounded; the anode of the fifth diode D10 Connected to the ground terminal GND of the first voltage regulator U11 and grounded; the other end of the second inductor L3 is connected to the input terminal of the second voltage conversion circuit 402 and the input of the third voltage conversion circuit 403 end connection.

In one embodiment, as shown in Figure 6, the first voltage conversion circuit 401 further includes: an eighth capacitor C67 and a ninth capacitor C68; wherein one end of the eighth capacitor C67 is connected to the second inductor L3 The other end of the eighth capacitor C67 is connected to the ground; the ninth capacitor C68 is connected in parallel with the eighth capacitor C67.

In one embodiment, as shown in Figure 7, the second voltage conversion circuit 402 includes: a second voltage regulator U10, a tenth capacitor C73, an eleventh capacitor C74, a twelfth capacitor C65, a thirteenth capacitor C66 and the fourteenth capacitor C69; wherein, the power supply terminal VIN of the second voltage regulator U10 is connected to the other end of the second inductor L3; the ground terminal GND of the second voltage regulator U10 is grounded; the The output terminal OUT of the second voltage regulator U10 is connected to the first load;

One end of the tenth capacitor C73 is connected to the other end of the second inductor L3, and the other end is connected to ground; the eleventh capacitor C74 is connected in parallel with the tenth capacitor C73; one end of the twelfth capacitor C65 is connected to The output end OUT of the second voltage regulator U10 is connected, and the other end is grounded; the thirteenth capacitor C66 and the fourteenth capacitor C69 are both connected in parallel with the twelfth capacitor C65.

In one embodiment, as shown in Figure 8, the third voltage conversion circuit 403 includes: a boost converter U7, a fourth inductor L4, a sixth diode D7, a fifteenth capacitor C48, a sixteenth capacitor C45, the sixth resistor R38 and the seventh resistor R44; wherein, the power supply terminal VIN of the boost converter U7 is connected to the other end of the second inductor L3 and one end of the fourth inductor L4, and the fourth The other end of the inductor L4 is connected to the switch terminal SW of the boost converter U7 and the anode of the sixth diode D7, and the cathode of the sixth diode D7 is connected to the second load and the anode of the sixth diode D7. One end of the fifteenth capacitor C48 is connected; the other end of the fifteenth capacitor C48 is connected with the feedback terminal FB of the boost converter U7; one end of the sixth resistor R38 is connected with the sixth diode D7 The cathode is connected, and the other end of the sixth resistor R38 is connected to the feedback terminal FB of the boost converter U7; one end of the seventh resistor R44 is connected to the feedback terminal FB of the boost converter U7, and the The other end of the seventh resistor R44 is grounded; one end of the sixteenth capacitor C45 is connected to the cathode of the sixth diode D7, and the other end of the sixteenth capacitor C45 is grounded.

In one embodiment, as shown in Figure 9, the amplification circuit 50 includes: a second MOS transistor Q5 and a seventh diode D6; wherein the drain of the second MOS transistor Q5 is connected to the charging circuit 10 The output terminal of the seventh diode D6 is connected to the anode of the seventh diode D6; the cathode of the seventh diode D6 is connected to the source of the second MOS transistor Q5 and the input terminal of the switch circuit 30; the The gate of the second MOS transistor Q5 is grounded.

Here's how this application works:

The battery charging tube U9 receives the first voltage provided by the external power supply and stores electrical energy; and converts the first voltage into a second voltage and outputs it to the third diode D4, the fourth diode D5, The sampling circuit 20 and the switch TS1 composed of the second resistor R28, the third resistor R29, the fourth resistor R31, the first capacitor C33 and the second capacitor C34 can be considered as the other end of the switch TS1 is also connected to the first voltage regulator U11. The switch TS1 is operated to conduct or disconnect the path between the charging circuit 10 and the discharging circuit 40; the sampling circuit 20 outputs the obtained second voltage to the main control circuit; the first voltage regulator U11 converts the second voltage into The third voltage is then output to the second voltage regulator U10 and the boost converter U7; the second voltage regulator U10 converts the third voltage into a fourth voltage and then outputs it to the first load; the boost converter U7 converts the third voltage into After being converted into the fifth voltage, it is output to the second load. This application obtains the first voltage provided by the external power supply through the charging circuit, stores the electric energy, and at the same time converts the first voltage into the second voltage and outputs it to the sampling circuit and the switching circuit; the switching circuit controls the charging circuit and the discharging circuit to be on or off. Open; the discharge circuit converts the second voltage into the fourth voltage and the fifth voltage, and outputs them to the first load and the second load; at the same time, the sampling circuit outputs the second voltage to the main control circuit; so that the power supply circuit has the sampling function , it is convenient to sample the second voltage output by the charging circuit and output it to the main control circuit, which improves the efficiency of the power supply circuit.

What is disclosed above is only the preferred embodiment of the present invention. Of course, it cannot be used to limit the scope of rights of the present utility model. Therefore, equivalent changes made according to the claims of the present utility model still fall within the scope of the present utility model.

Claims (10)

1. A power supply circuit with sampling function, comprising:

the input end of the charging circuit is connected with an external power supply, the output end of the charging circuit is connected with the input end of the sampling circuit and the input end of the switching circuit, and the charging circuit is used for receiving a first voltage provided by the external power supply and storing electric energy; the first voltage is converted into a second voltage and then output to the sampling circuit and the switching circuit;

the output end of the sampling circuit is connected with the main control circuit and is used for acquiring the second voltage output by the charging circuit and outputting the second voltage to the main control circuit;

the output end of the switching circuit is connected with the input end of the discharging circuit and is used for controlling the connection or disconnection of a passage between the charging circuit and the discharging circuit;

the discharging circuit is connected with the first load and the second load at the output end, and is used for receiving the second voltage, converting the second voltage into a fourth voltage and a fifth voltage, and outputting the fourth voltage and the fifth voltage to the first load and the second load.

2. The power supply circuit with sampling function according to claim 1, further comprising:

and the input end of the amplifying circuit is connected with the output end of the charging circuit, and the output end of the amplifying circuit is connected with the input end of the switching circuit and is used for amplifying the second voltage output by the charging circuit and outputting the second voltage to the switching circuit.

3. The power supply circuit with sampling function according to claim 1, wherein the discharging circuit comprises:

the input end of the first voltage conversion circuit is connected with the output end of the charging circuit, and the output end of the first voltage conversion circuit is connected with the input end of the second voltage conversion circuit and the input end of the third voltage conversion circuit and is used for converting the second voltage into the third voltage and outputting the third voltage to the second voltage conversion circuit and the third voltage conversion circuit;

the output end of the second voltage conversion circuit is connected with the first load and is used for converting the third voltage into a fourth voltage and outputting the fourth voltage to the first load;

and the output end of the third voltage conversion circuit is connected with the second load and is used for converting the third voltage into a fifth voltage and outputting the fifth voltage to the second load.

4. The power supply circuit with sampling function according to claim 1, wherein the charging circuit comprises: the device comprises a battery charging tube, a first MOS tube, a first diode, a second diode, a first inductor and a first resistor;

the switching circuit includes: a switch;

the power supply end of the battery charging tube is connected with the external power supply;

the driving end of the battery charging tube is connected with the grid electrode of the first MOS tube;

the source electrode of the first MOS tube is connected with an external power supply, the drain electrode of the first MOS tube is connected with the anode of the first diode, the cathode of the first diode is connected with one end of the first inductor, the other end of the first inductor is connected with the current detection end of the battery charging tube and one end of the first resistor, the other end of the first resistor is connected with one end of the switch and the input end of the sampling circuit, and the other end of the switch is connected with the input end of the discharging circuit.

5. The power supply circuit with sampling function according to claim 4, wherein the sampling circuit comprises: a third diode, a fourth diode, a second resistor, a third resistor, a fourth resistor, a first capacitor and a second capacitor;

the cathode of the third diode is connected with the output end of the charging circuit, and the anode of the third diode is grounded;

the cathode of the fourth diode is connected with the cathode of the third diode, and the anode of the fourth diode is grounded;

one end of the second resistor is connected with the cathode of the third diode, and the other end of the second resistor is connected with the cathode of the fourth diode;

one end of the third resistor is connected with the cathode of the fourth diode, the other end of the third resistor is connected with the input end of the main control circuit and one end of the fourth resistor, and the other end of the fourth resistor is grounded;

one end of the first capacitor is connected with one end of the second resistor, which is close to the third diode, and the other end of the first capacitor is grounded;

one end of the second capacitor is connected with the end, close to the fourth diode, of the second resistor, and the other end of the second capacitor is grounded.

6. A power supply circuit with sampling function according to claim 3, wherein the first voltage conversion circuit comprises: a third capacitor, a fourth capacitor, a fifth capacitor, a first voltage regulator, a sixth capacitor, a seventh capacitor, a fifth resistor, a fifth diode and a second inductor;

one end of the third capacitor is connected with the output end of the charging circuit and the power supply end of the first voltage stabilizer, and the other end of the third capacitor is grounded;

the fourth capacitor and the fifth capacitor are connected in parallel with the third capacitor;

the high-side power end of the first voltage stabilizer is connected with one end of the second inductor and the cathode of the fifth diode;

the frequency compensation end of the first voltage stabilizer is connected with one end of the sixth capacitor, the other end of the sixth capacitor is connected with one end of the fifth resistor, and the other end of the fifth resistor is grounded; one end of the seventh capacitor is connected with the frequency compensation end of the first voltage stabilizer, and the other end of the seventh capacitor is grounded;

the anode of the fifth diode is connected with the grounding end of the first voltage stabilizer and grounded;

the other end of the second inductor is connected with the input end of the second voltage conversion circuit and the input end of the third voltage conversion circuit.

7. The power supply circuit with sampling function according to claim 6, wherein the first voltage conversion circuit further comprises: an eighth capacitance and a ninth capacitance;

one end of the eighth capacitor is connected with the other end of the second inductor, and the other end of the eighth capacitor is grounded;

the ninth capacitor is connected in parallel with the eighth capacitor.

8. The power supply circuit with sampling function according to claim 7, wherein the second voltage conversion circuit comprises: a second voltage regulator, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, and a fourteenth capacitor;

the power supply end of the second voltage stabilizer is connected with the other end of the second inductor;

the grounding end of the second voltage stabilizer is grounded;

the output end of the second voltage stabilizer is connected with the first load;

one end of the tenth capacitor is connected with the other end of the second inductor, and the other end of the tenth capacitor is grounded;

the eleventh capacitor is connected in parallel with the tenth capacitor;

one end of the twelfth capacitor is connected with the output end of the second voltage stabilizer, and the other end of the twelfth capacitor is grounded;

the thirteenth capacitor and the fourteenth capacitor are connected in parallel with the twelfth capacitor.

9. The power supply circuit with a sampling function according to claim 8, wherein the third voltage conversion circuit includes: a boost converter, a fourth inductor, a sixth diode, a fifteenth capacitor, a sixteenth capacitor, a sixth resistor and a seventh resistor;

the power supply end of the boost converter is connected with the other end of the second inductor and one end of the fourth inductor, the other end of the fourth inductor is connected with the switch end of the boost converter and the anode of the sixth diode, and the cathode of the sixth diode is connected with the second load and one end of the fifteenth capacitor;

the other end of the fifteenth capacitor is connected with the feedback end of the boost converter;

one end of the sixth resistor is connected with the cathode of the sixth diode, and the other end of the sixth resistor is connected with the feedback end of the boost converter;

one end of the seventh resistor is connected with the feedback end of the boost converter, and the other end of the seventh resistor is grounded;

one end of the sixteenth capacitor is connected with the cathode of the sixth diode, and the other end of the sixteenth capacitor is grounded.

10. The power supply circuit with a sampling function according to claim 2, wherein the amplifying circuit includes: a second MOS tube and a seventh diode;

the drain electrode of the second MOS tube is connected with the output end of the charging circuit and the anode of the seventh diode;

the cathode of the seventh diode is connected with the source electrode of the second MOS tube and the input end of the switching circuit;

and the grid electrode of the second MOS tube is grounded.