An electronic device power supply circuit

Abstract

The utility model relates to electronic equipment power supply circuit technical field especially, a kind of electronic equipment power supply circuit, comprising: total power supply connecting end, secondary power supply connecting end, load connecting end, current-limiting switch chip, MCU control chip, NMOS tube;Wherein, the MCU control chip is connected with secondary power supply connecting end, NMOS tube, current-limiting switch chip respectively, the current-limiting switch chip is also connected with total power supply connecting end, load connecting end respectively, the NMOS tube is also connected with load connecting end. The size of the input voltage of electronic equipment is detected by MCU control chip with fixed frequency, when MCU control chip does not detect the condition that input voltage has obvious drop, MCU control chip control circuit continues to steadily increase the size of output current;When MCU control chip detects the condition that input voltage has obvious drop, MCU control chip sends instruction to limit the output current of circuit, and with suitable size output current, it is stable to power supply for electronic equipment.

Description

Technical Field

[0001] This utility model relates to the field of power supply circuit technology for electronic devices, and in particular to a power supply circuit for electronic devices. Background Technology

[0002] Most charging docks for electronic devices on the market specify the voltage range of the input power supply. When the charging dock is connected to a power source within the specified voltage range, it will provide a stable power supply to the device. However, when the power supply of the external power source connected to the charging dock is insufficient to support the charging needs of the electronic device, it will cause a significant drop in the input voltage of the external power source. As a result, the working state of the input power source will be interfered with. Not only will it fail to provide a stable power supply to the charging dock, but it may also be unable to maintain its own working state and stop operating. Utility Model Content

[0003] This utility model provides a power supply circuit for electronic devices to solve the defect in the prior art where the working state of both the charging base and the external power supply becomes unstable when the charging base of an electronic device is connected to an external power source that does not meet its own power supply requirements. It realizes real-time detection of voltage drop of the input power source and precise adjustment of the output current of the charging base to provide stable power supply for the device.

[0004] This utility model provides a power supply circuit for an electronic device, including: a main power connection terminal, a secondary power connection terminal, a load connection terminal, a current limiting switch chip, an MCU control chip, and an NMOS transistor;

[0005] The MCU control chip is connected to the secondary power supply terminal, the NMOS transistor, and the current limiting switch chip. The current limiting switch chip is also connected to the main power supply terminal and the load terminal. The NMOS transistor is also connected to the load terminal.

[0006] According to the present invention, an electronic device power supply circuit is provided, wherein the current limiting switch chip has 6 pins. Its A1 pin and C1 pin are both connected to the load connection terminal, its B1 pin is connected to the main power connection terminal, its B2 pin is grounded, its A2 pin is connected to the MCU control chip through the fourth resistor, its C2 pin is grounded through the fifth resistor and the third resistor in sequence, its B1 pin is also grounded through the second resistor, and its C2 pin is also connected to the MCU control chip.

[0007] According to the power supply circuit of the electronic device provided by this utility model, the B1 pin of the current limiting switch chip is also grounded through the seventh capacitor, the C2 pin is also grounded through the third capacitor, the C1 pin is also grounded through the fifth capacitor, and the A1 pin is also grounded through the sixth capacitor.

[0008] According to the power supply circuit of the electronic device provided by this utility model, pin 1 of the NMOS transistor is connected to the MCU control chip through the sixth resistor, pin 2 is grounded, and pin 3 is connected to the load connection terminal through the eighth, ninth, tenth and eleventh resistors in parallel.

[0009] According to the power supply circuit for an electronic device provided by this utility model, pin 1 of the NMOS transistor is also grounded through a seventh resistor.

[0010] According to the present invention, the power supply circuit for an electronic device includes an MCU control chip whose NRST pin is connected to the power supply terminal of the next stage via a first resistor, the MCU control chip whose VDDA and VDD pins are respectively connected to the power supply terminal of the next stage, the VSS pin is grounded, the PB6 pin is connected to pin 1 of the NMOS transistor, the PA1 pin is connected to the C2 pin of the current limiting switch chip, and the PB7 pin is connected to the A2 pin of the current limiting switch chip.

[0011] According to the power supply circuit of the electronic device provided by this utility model, the NRST pin of the MCU control chip is also grounded through a first capacitor, the VDDA pin is also grounded through a second capacitor, and the VDD pin is also grounded through a fourth capacitor.

[0012] According to the power supply circuit of the electronic device provided by this utility model, the VDD pin of the MCU control chip is grounded after passing through the twelfth resistor and the thirteenth resistor in sequence, and the PB9-BOOT0 pin is connected to the line connecting the twelfth resistor and the thirteenth resistor.

[0013] This utility model provides a power supply circuit for an electronic device. The MCU control chip detects the input voltage of the electronic device at a fixed frequency. When the MCU control chip does not detect a significant drop in input voltage, the MCU control chip controls the circuit to continue to steadily increase the output current. When the MCU control chip detects a significant drop in input voltage, the MCU control chip sends a command to limit the output current of the circuit and provides stable power to the electronic device with an appropriate output current. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a circuit diagram of a power supply circuit for an electronic device provided by this utility model;

[0016] Figure 2 This is a schematic diagram of the connections of each pin of the MCU control chip;

[0017] Figure 3 This is an electrical block diagram of a power supply circuit for an electronic device provided by this utility model. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0019] The following is combined Figures 1-3 This invention describes a power supply circuit for an electronic device, comprising: a main power supply connection terminal, a secondary power supply connection terminal, a load connection terminal, a current limiting switch chip U1, an MCU control chip U2, and an NMOS transistor Q1; wherein, the MCU control chip U2 is connected to the secondary power supply connection terminal, the NMOS transistor Q1, and the current limiting switch chip U1, the current limiting switch chip U1 is also connected to the main power supply connection terminal and the load connection terminal, and the NMOS transistor Q1 is also connected to the load connection terminal.

[0020] The current limiting switch chip U1 is model YHM2510, which has 6 pins: A1, A2, B1, B2, C1, and C2. Pins A1 and C1 of the current limiting switch chip U1 are connected to the load connection terminal, pin B1 is connected to the main power connection terminal, pin B2 is grounded, pin A2 is connected to the MCU control chip U2 through the fourth resistor R4, pin C2 is grounded through the fifth resistor R5 and the third resistor R3, pin B1 of the current limiting switch chip U1 is also grounded through the second resistor R2, and pin C2 of the current limiting switch chip U1 is also connected to the MCU control chip U2.

[0021] Furthermore, the C2 pin of the current limiting switch chip U1 is also connected between the line connecting the second resistor R2 and the third resistor R3.

[0022] Furthermore, pin B1 of the current limiting switch chip U1 is grounded through the seventh capacitor C7, pin C2 is grounded through the third capacitor C3, pin C1 is grounded through the fifth capacitor C5, and pin A1 is grounded through the sixth capacitor C6.

[0023] Pin 1 of NMOS transistor Q1 is connected to MCU control chip U2 through resistor R6, pin 2 is grounded, and pin 3 is connected to the load terminal through resistors R8, R9, R10, and R11 in parallel.

[0024] Furthermore, pin 1 of the NMOS transistor Q1 is grounded through the seventh resistor R7.

[0025] In this embodiment, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11, which are connected in parallel, are equivalent to an external load. When the NMOS transistor Q1 is turned on, the positive terminal of the power supply, the load, the parallel resistor, and the negative terminal of the power supply form a loop, which converts the excessive current in the circuit into heat energy and dissipates it, preventing the circuit from being unstable due to the large output current affecting the input voltage drop.

[0026] The NRST pin of the MCU control chip U2 is connected to the power supply terminal of the subsequent stage through the first resistor R1. The VDDA and VDD pins of the MCU control chip U2 are connected to the power supply terminal of the subsequent stage respectively. The VSS pin is grounded. The PB6 pin is connected to pin 1 of the NMOS transistor Q1. The PA1 pin is connected to the C2 pin of the current limiting switch chip U1. The PB7 pin is connected to the A2 pin of the current limiting switch chip U1.

[0027] Furthermore, the NRST pin of the MCU control chip U2 is also grounded through the first capacitor C1, the VDDA pin is also grounded through the second capacitor C2, and the VDD pin is also grounded through the fourth capacitor C4.

[0028] Furthermore, the VDD pin of the MCU control chip U2 is grounded through the twelfth resistor R12 and the thirteenth resistor R13 in sequence, and the PB9-BOOT0 pin is connected to the line connecting the twelfth resistor R12 and the thirteenth resistor R13.

[0029] In this embodiment, the MCU control chip U2 is an STM32L011F4. Its MCU_ADC pin detects the input voltage drop in real time, the MCU_ACMD pin controls the output current of the circuit to gradually increase, and the MCU_IDET_CTRL pin controls the conduction and disconnection of the NMOS transistor Q1, so as to achieve precise control of the output current of the power supply circuit and provide stable power supply to the load.

[0030] Specifically, after the charging dock is connected to the main power supply, the input voltage gradually stabilizes after voltage division and filtering by the circuit. At this time, the MCU_IDET_CTRL pin of the MCU control chip U2 controls pin 1 of NMOS transistor Q1 to be in a high-level state, forming a voltage difference between pins 1 and 2 of NMOS transistor Q1. NMOS transistor Q1 is turned on, so that the positive terminal of the input power supply, the load, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11 in parallel, and the negative terminal of the power supply form a loop. At the same time, the MCU_ACMD pin of the MCU control chip U2 controls the output current of the circuit to gradually increase at fixed intervals (such as 30mA, 50mA) through the A2 pin of the current limiting switch chip U1. The MCU_ADC pin of the MCU control chip U2 detects the drop in input voltage in real time after each increase in output current through the C2 pin of the current limiting switch chip U1.

[0031] When the circuit's output current does not reach the input power supply limit, the MCU_ADC pin of the MCU control chip U2 detects that the circuit's input voltage is within the normal supply voltage range and there is no significant drop. At this time, the input voltage will remain stable to supply power to the load. When the circuit's output current continues to increase until it approaches or even exceeds the input power supply limit, the MCU_ADC pin of the MCU control chip U2 will detect a significant drop in the circuit's input voltage. At this time, the MCU_ACMD pin of the MCU control chip U2 stops sending current increase commands to the A2 pin of the current limiting switch chip U1 and flexibly controls the output current of the A1 and C1 pins of the current limiting switch chip U1 to further limit the circuit's output current until both the input power supply and the charging base are in a stable operating state. At this time, the circuit's output current is the maximum supply capacity of the input power supply, and the MCU_ACMD pin of the MCU control chip U2 controls the current limiting switch chip U1 to stably supply power to the load with the maximum output current at this time.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A power supply circuit for an electronic device, characterized in that, include: Main power supply connection terminal, secondary power supply connection terminal, load connection terminal, current limiting switch chip, MCU control chip, NMOS transistor; The MCU control chip is connected to the secondary power supply terminal, the NMOS transistor, and the current limiting switch chip. The current limiting switch chip is also connected to the main power supply terminal and the load terminal. The NMOS transistor is also connected to the load terminal.

2. The power supply circuit for an electronic device according to claim 1, characterized in that, The current limiting switch chip has 6 pins. Pins A1 and C1 are connected to the load connection terminal, pin B1 is connected to the main power connection terminal, pin B2 is grounded, pin A2 is connected to the MCU control chip through the fourth resistor, pin C2 is grounded through the fifth resistor and the third resistor in sequence, pin B1 of the current limiting switch chip is also grounded through the second resistor, and pin C2 of the current limiting switch chip is also connected to the MCU control chip.

3. The power supply circuit for an electronic device according to claim 2, characterized in that, The B1 pin of the current limiting switch chip is also grounded through the seventh capacitor, the C2 pin is also grounded through the third capacitor, the C1 pin is also grounded through the fifth capacitor, and the A1 pin is also grounded through the sixth capacitor.

4. The power supply circuit for an electronic device according to claim 3, characterized in that, Pin 1 of the NMOS transistor is connected to the MCU control chip through the sixth resistor, pin 2 is grounded, and pin 3 is connected to the load terminal through the eighth, ninth, tenth, and eleventh resistors in parallel.

5. The power supply circuit for an electronic device according to claim 4, characterized in that, Pin 1 of the NMOS transistor is also grounded through a seventh resistor.

6. The power supply circuit for an electronic device according to claim 4, characterized in that, The NRST pin of the MCU control chip is connected to the power supply terminal of the subsequent stage through the first resistor. The VDDA and VDD pins of the MCU control chip are respectively connected to the power supply terminal of the subsequent stage. The VSS pin is grounded. The PB6 pin is connected to pin 1 of the NMOS transistor. The PA1 pin is connected to the C2 pin of the current limiting switch chip. The PB7 pin is connected to the A2 pin of the current limiting switch chip.

7. The power supply circuit for an electronic device according to claim 6, wherein The NRST pin of the MCU control chip is also grounded through a first capacitor, the VDDA pin is also grounded through a second capacitor, and the VDD pin is also grounded through a fourth capacitor.

8. The power supply circuit for an electronic device according to claim 7, wherein The VDD pin of the MCU control chip is grounded after passing through the twelfth and thirteenth resistors in sequence, and the PB9-BOOT0 pin is connected to the line connecting the twelfth and thirteenth resistors.

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