Synchronous rectification power supply circuit based on microcontroller

Abstract

The utility model discloses a synchronous rectification power supply circuit based on a microcontroller. The synchronous rectification power supply circuit is characterized in that the output end of the microcontroller is electrically connected with a power MOS tube driving circuit; the output end of the power MOS tube driving circuit is connected with the input end of the power conversion circuit; the output end of the power conversion circuit is connected with the direct-current power output circuit; the input end of the voltage signal acquisition circuit and the input end of the current signal acquisition circuit are respectively connected with the output end of the power conversion circuit; the input end of the voltage signal acquisition circuit and the output end of the current signal acquisition circuit are respectively connected with the microcontroller; and the output end of the power supply is connected with the microcontroller, the power MOS tube driving circuit and the power conversion circuit. According to the invention, the output voltage and current can be flexibly adjusted; and meanwhile, the PWM waveform is generated through the microcontroller, so that the dependence on external components is reduced, and the required PCB area is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of power supply voltage conversion, and in particular to a synchronous rectification power supply circuit. Background Art

[0002] In the current field of electronic equipment, especially in mobile and handheld mobile equipment products, these devices usually need to achieve efficient power conversion and management in a limited space to meet the voltage and current requirements of different components. Regulated power supplies of various voltage values ​​are often used, sometimes a DC boost power supply circuit is used, and sometimes a DC step-down power supply is used.

[0003] The traditional DC-DC power conversion circuit, although using a dedicated integrated circuit to achieve the boost or buck function, is generally implemented by using a dedicated integrated circuit in combination with complex peripheral devices. In order for the circuit to work properly, many necessary components need to be configured on its periphery, which not only makes the circuit structure complicated, but also occupies a large PCB area, bringing difficulties to the miniaturization of equipment, increasing production costs, reducing product competitiveness, and is not conducive to the wide promotion and application of products. Moreover, the boost or buck power supply realized by the general dedicated integrated circuit has a fixed output voltage, and its firmware characteristics cannot be changed without changing the hardware circuit. The conversion efficiency is low, and the circuit generally has a simple constant voltage and overcurrent protection function. The fixed constant voltage output cannot achieve flexible voltage and current adjustment functions. Summary of the invention

[0004] Based on this, in order to solve the above technical problems, a microcontroller-based synchronous rectification power supply circuit is provided to solve the problems that the prior art occupies a large PCB area and cannot realize flexible voltage and current adjustment functions.

[0005] A synchronous rectification power supply circuit based on a microcontroller, the circuit comprising: a microcontroller, a power MOS tube driving circuit, a power conversion circuit, a DC power output circuit, a voltage signal acquisition circuit, a current signal acquisition circuit and a power supply;

[0006] The output end of the microcontroller is electrically connected to the power MOS tube drive circuit; the output end of the power MOS tube drive circuit is connected to the input end of the power conversion circuit; the output end of the power conversion circuit is connected to the DC power output circuit;

[0007] The input end of the voltage signal acquisition circuit and the input end of the current signal acquisition circuit are respectively connected to the output end of the power conversion circuit; the input end of the voltage signal acquisition circuit and the output end of the current signal acquisition circuit are respectively connected to the microcontroller;

[0008] The output end of the power supply is connected to the microcontroller, the power MOS tube driving circuit and the power conversion circuit.

[0009] In the above solution, optionally, the power conversion circuit includes: MOS transistor Q1, MOS transistor Q2, MOS transistor Q3, MOS transistor Q4, inductor L1, inductor L2, capacitor C3 and capacitor C4;

[0010] The source of the MOS transistor Q1 is connected to the drain of the MOS transistor Q3, and the source of the MOS transistor Q2 is connected to the drain of the MOS transistor Q4 in series; the drain of the MOS transistor Q1 is the VCC terminal, and the source of the MOS transistor Q3 is grounded; the drain of the MOS transistor Q2 is the VCC terminal, and the source of the MOS transistor Q4 is grounded;

[0011] A third node is provided on the connection line between the MOS transistor Q1 and the MOS transistor Q3, a third branch is led out from the third node, the third branch is connected to the inductor L1 and the inductor L2 in sequence, and then connected to the connection line between the MOS transistor Q2 and the MOS transistor Q4;

[0012] A fourth node is provided on the connection line between the inductor L1 and the inductor L2, a fourth branch is led out from the fourth node, and the fourth branch is connected to the capacitor C3 and then to the source of the MOS tube Q3;

[0013] A fifth node is provided on the connection line between the inductor L1 and the inductor L2, a fifth branch is led out from the fifth node, and the fourth branch is connected to the capacitor C4 and then to the source of the MOS tube Q4.

[0014] In the above scheme, optionally, the circuit further includes: a current signal amplification circuit, a voltage analog-to-digital conversion protection circuit and a current analog-to-digital feedback circuit;

[0015] The voltage signal acquisition circuit is connected to the microcontroller via a voltage analog-to-digital conversion protection circuit;

[0016] The current signal acquisition circuit is connected to the microcontroller via a current analog-to-digital conversion protection circuit and a current signal amplification circuit in sequence.

[0017] In the above solution, further optionally, the current signal acquisition circuit includes: a sampling resistor R2; the current signal amplification circuit includes: a resistor R1, a capacitor C5, and an operational amplifier U2;

[0018] The resistor R2 is connected to the output end of the power conversion circuit; the inverting input end of the operational amplifier is grounded; the output end of the operational amplifier is connected to one end of the resistor R1; a sixth node is set at the other end of the resistor R1, and a sixth branch is led out from the sixth node and the capacitor C5 and then grounded.

[0019] In the above solution, further optionally, the resistance of the sampling resistor R2 is 5 milliohms.

[0020] In the above solution, optionally, the voltage signal acquisition circuit includes: a resistor R3, a resistor R4 and a capacitor C1;

[0021] The resistor R3 and the resistor R4 are connected in series, a fifth node is set at the connection between the resistor R3 and the resistor R4, a seventh branch is drawn out from the seventh node, connected in series with the capacitor C1, and then connected to the end of the resistor R4 away from R3; the end of the resistor R4 away from R3 is grounded.

[0022] In the above solution, optionally, the power MOS tube driving circuit adopts a chip of model FD6288.

[0023] In the above solution, optionally, the microcontroller adopts a 32-bit ARM microprocessor.

[0024] In the above solution, optionally, the power supply includes: a power supply input circuit and a voltage reduction circuit;

[0025] After being connected, the power supply input circuit and the step-down circuit are respectively connected to the microcontroller, the power MOS tube driving circuit, the power conversion circuit, the DC power output circuit, the voltage feedback circuit and the current feedback circuit.

[0026] This application has at least the following beneficial effects:

[0027] In this application, a microcontroller generates a PWM pulse width modulation waveform, and then a MOS drive circuit controls two half-bridge power conversion circuits to achieve the function of voltage conversion. This allows flexible adjustment of output voltage and current to adapt to different load requirements and application scenarios. In addition, by generating a PWM pulse width modulation waveform through a microcontroller, the dependence on external components is reduced, thereby significantly reducing the required PCB area. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a microcontroller-based synchronous rectification power supply circuit provided in one embodiment of the present application;

[0029] Figure 2 A circuit schematic diagram of a microcontroller provided in one embodiment of the present application;

[0030] Figure 3 A circuit schematic diagram of a power conversion circuit provided in one embodiment of the present application;

[0031] Figure 4 A schematic diagram of a voltage analog-to-digital conversion protection circuit provided in one embodiment of the present application;

[0032] Figure 5A schematic diagram of a current analog-to-digital conversion circuit provided in one embodiment of the present application;

[0033] Figure 6 A schematic diagram of a current signal acquisition circuit provided in one embodiment of the present application;

[0034] Figure 7 A schematic diagram of a current signal amplification circuit is provided for one embodiment of the present application;

[0035] Figure 8 A schematic diagram of a voltage signal acquisition circuit provided in accordance with an embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0037] In the description of this application: unless otherwise specified, the meaning of "plurality" is two or more. The terms "first", "second", "third", etc. in this application are intended to distinguish the objects referred to, and do not have special meanings in terms of technical connotations (for example, they should not be understood as emphasizing the importance or order, etc.). Expressions such as "including", "comprising", "having", etc. also mean "not limited to" (certain units, components, materials, steps, etc.).

[0038] In one embodiment, Figure 1 As shown, a synchronous rectification power supply circuit based on a microcontroller is provided, and the circuit includes: a microcontroller, a power MOS tube driving circuit, a power conversion circuit, a DC power output circuit, a voltage signal acquisition circuit, a current signal acquisition circuit and a power supply;

[0039] The output end of the microcontroller is electrically connected to the power MOS tube drive circuit; the output end of the power MOS tube drive circuit is connected to the input end of the power conversion circuit; the output end of the power conversion circuit is connected to the DC power output circuit;

[0040] The input end of the voltage signal acquisition circuit and the input end of the current signal acquisition circuit are respectively connected to the output end of the power conversion circuit; the input end of the voltage signal acquisition circuit and the output end of the current signal acquisition circuit are respectively connected to the microcontroller;

[0041] The output end of the power supply is connected to the microcontroller, the power MOS tube driving circuit and the power conversion circuit.

[0042] Specifically, Figure 2As shown in the figure, the microcontroller uses a low-power 32-bit ARM microcontroller, uses the on-chip advanced timer to generate two complementary PWM waveforms, drives the power MOS tube switch, and realizes power conversion. The on-chip ADC is used to monitor the output voltage and output current, and then the duty cycle of the PWM wave is adjusted according to the ADC value, thereby forming a closed-loop control of power conversion, which is the core control component of this controller.

[0043] In the above-mentioned microcontroller-based synchronous rectification power supply circuit, the microcontroller generates a PWM pulse width modulation waveform, and then the MOS drive circuit controls the two half-bridge power conversion circuits to achieve the voltage conversion function. This enables flexible adjustment of the output voltage and current to adapt to different load requirements and application scenarios. In addition, by generating the PWM pulse width modulation waveform through the microcontroller, the dependence on external components is reduced, thereby significantly reducing the required PCB area.

[0044] In one embodiment, Figure 3 As shown, the power conversion circuit includes: MOS tube Q1, MOS tube Q2, MOS tube Q3, MOS tube Q4, inductor L1, inductor L2, capacitor C3 and capacitor C4;

[0045] The source of the MOS transistor Q1 is connected to the drain of the MOS transistor Q3, and the source of the MOS transistor Q2 is connected to the drain of the MOS transistor Q4 in series; the drain of the MOS transistor Q1 is the VCC terminal, and the source of the MOS transistor Q3 is grounded; the drain of the MOS transistor Q2 is the VCC terminal, and the source of the MOS transistor Q4 is grounded;

[0046] A third node is provided on the connection line between the MOS transistor Q1 and the MOS transistor Q3, a third branch is led out from the third node, the third branch is connected to the inductor L1 and the inductor L2 in sequence, and then connected to the connection line between the MOS transistor Q2 and the MOS transistor Q4;

[0047] A fourth node is provided on the connection line between the inductor L1 and the inductor L2, a fourth branch is led out from the fourth node, and the fourth branch is connected to the capacitor C3 and then to the source of the MOS tube Q3;

[0048] A fifth node is provided on the connection line between the inductor L1 and the inductor L2, a fifth branch is led out from the fifth node, and the fourth branch is connected to the capacitor C4 and then to the source of the MOS tube Q4.

[0049] Specifically, the power conversion circuit uses a low-resistance N-type MOS tube. Every two MOS tubes form a half-bridge circuit. A power inductor is connected at the center of the half-bridge circuit. The other end of the inductor is connected to the positive electrode of the electrolytic capacitor, and the negative electrode of the capacitor is grounded. When the high-order MOS tube is turned on, the inductor is magnetized and the filter capacitor is charged at the same time. When the low-order MOS tube is turned on, the magnetism is released to generate a continuous flow to output electrical energy to the load.

[0050] In one embodiment, Figure 4 and Figure 5 As shown, the circuit also includes: a current signal amplification circuit, a voltage analog-to-digital conversion protection circuit and a current analog-to-digital feedback circuit;

[0051] The voltage signal acquisition circuit is connected to the microcontroller via a voltage analog-to-digital conversion protection circuit;

[0052] The current signal acquisition circuit is connected to the microcontroller via a current analog-to-digital conversion protection circuit and a current signal amplification circuit in sequence.

[0053] In one embodiment, Figure 6 As shown, the current signal acquisition circuit includes: a sampling resistor R2; the current signal amplification circuit includes: a resistor R1, a capacitor C5, and an operational amplifier U2;

[0054] The resistor R2 is connected to the output end of the power conversion circuit; the inverting input end of the operational amplifier is grounded; the output end of the operational amplifier is connected to one end of the resistor R1; a sixth node is set at the other end of the resistor R1, and a sixth branch is led out from the sixth node and the capacitor C5 and then grounded.

[0055] Specifically, a 5 milliohm high-precision resistor is used as a current sampling resistor, and the current signal is amplified by a rail-to-rail precision operational amplifier. The amplified signal is converted from analog to digital by the ADC soft conversion circuit of the microcontroller.

[0056] In one embodiment, Figure 7 As shown, the voltage signal acquisition circuit includes: a resistor R3, a resistor R4 and a capacitor C1;

[0057] The resistor R3 and the resistor R4 are connected in series, a fifth node is set at the connection between the resistor R3 and the resistor R4, a seventh branch is drawn out from the seventh node, connected in series with the capacitor C1, and then connected to the end of the resistor R4 away from R3; the end of the resistor R4 away from R3 is grounded.

[0058] Specifically, the voltage signal acquisition circuit adopts a resistor voltage division mode. After each input and output voltage passes through the voltage division circuit, it is divided into the range that the ADC circuit can read. A filtering circuit should also be added to the circuit to reduce the impact of voltage signal fluctuations on the ADC, and to increase the protection circuit of the microcontroller ADC pin - voltage limiting circuit, anti-static circuit, and TVS circuit.

[0059] In one embodiment, the power MOS tube driving circuit uses a chip of model FD6288. The FD6288 chip is a dedicated MOS tube driving chip with strong driving capability and very stable performance in actual use. A single chip can drive three groups of MOS half-bridge circuits with fast response speed. The built-in floating bridge lifting circuit can realize the driving of high-position NMOS tubes without an external boost power supply.

[0060] In one embodiment, the power supply includes: a power supply input circuit and a step-down circuit; after being connected, the power supply input circuit and the step-down circuit are respectively connected to the microcontroller, the power MOS tube drive circuit, the power conversion circuit, the DC power output circuit, the voltage feedback circuit and the current feedback circuit.

[0061] The present invention can achieve the following effects:

[0062] (1) Flexible voltage and current adjustment can be achieved, and the output can be adjusted according to different working modes and different working parameters, so that it can adapt to various complex applications. The output voltage and current are controllable, and the automatic adjustment function of the power supply enables the power supply to maintain a stable output voltage and current without external interference, and the output accuracy is higher. The conversion between various voltages is easy to achieve.

[0063] (2) Multiple protection functions to prevent power supply and load from damage.

[0064] (3) Reduce circuit PCB area and reduce costs.

[0065] (4) The use of dual power supplies can achieve bidirectional power transmission without changing any hardware circuits.

[0066] (5) Adapt to more complex application scenarios, such as solar power supply systems, where one power source is used to charge the battery through the solar panel, and the other power source is used to boost the voltage to the voltage required by the subsequent circuit to provide power for the subsequent circuit.

[0067] (6) Use synchronous rectification to perform voltage conversion, improve circuit efficiency, reduce heat generation, and reduce energy loss.

[0068] (7) Good stability, the rise and fall time of voltage and current can be adjusted.

[0069] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A synchronous rectification power supply circuit based on a microcontroller, characterized in that: The circuit includes: a microcontroller, a power MOS tube driving circuit, a power conversion circuit, a DC power output circuit, a voltage signal acquisition circuit, a current signal acquisition circuit and a power supply; The output end of the microcontroller is electrically connected to the power MOS tube drive circuit; the output end of the power MOS tube drive circuit is connected to the input end of the power conversion circuit; the output end of the power conversion circuit is connected to the DC power output circuit; The input end of the voltage signal acquisition circuit and the input end of the current signal acquisition circuit are respectively connected to the output end of the power conversion circuit; the input end of the voltage signal acquisition circuit and the output end of the current signal acquisition circuit are respectively connected to the microcontroller; The output end of the power supply is connected to the microcontroller, the power MOS tube driving circuit and the power conversion circuit.

2. The microcontroller-based synchronous rectification power supply circuit according to claim 1, characterized in that: The power conversion circuit includes: MOS tube Q1, MOS tube Q2, MOS tube Q3, MOS tube Q4, inductor L1, inductor L2, capacitor C3 and capacitor C4; The source of the MOS transistor Q1 is connected to the drain of the MOS transistor Q3, and the source of the MOS transistor Q2 is connected to the drain of the MOS transistor Q4 in series; the drain of the MOS transistor Q1 is the VCC terminal, and the source of the MOS transistor Q3 is grounded; the drain of the MOS transistor Q2 is the VCC terminal, and the source of the MOS transistor Q4 is grounded; A third node is provided on the connection line between the MOS transistor Q1 and the MOS transistor Q3, a third branch is led out from the third node, the third branch is connected to the inductor L1 and the inductor L2 in sequence, and then connected to the connection line between the MOS transistor Q2 and the MOS transistor Q4; A fourth node is provided on the connection line between the inductor L1 and the inductor L2, a fourth branch is led out from the fourth node, and the fourth branch is connected to the capacitor C3 and then to the source of the MOS tube Q3; A fifth node is provided on the connection line between the inductor L1 and the inductor L2, a fifth branch is led out from the fifth node, and the fourth branch is connected to the capacitor C4 and then to the source of the MOS tube Q4.

3. The microcontroller-based synchronous rectification power supply circuit according to claim 1, characterized in that: The circuit also includes: a current signal amplification circuit, a voltage analog-to-digital conversion protection circuit and a current analog-to-digital feedback circuit; The voltage signal acquisition circuit is connected to the microcontroller via a voltage analog-to-digital conversion protection circuit; The current signal acquisition circuit is connected to the microcontroller via a current analog-to-digital conversion protection circuit and a current signal amplification circuit in sequence.

4. The microcontroller-based synchronous rectification power supply circuit according to claim 3, characterized in that: The current signal acquisition circuit includes: a sampling resistor R2; the current signal amplification circuit includes: a resistor R1, a capacitor C5, and an operational amplifier U2; The resistor R2 is connected to the output end of the power conversion circuit; the inverting input end of the operational amplifier is grounded; the output end of the operational amplifier is connected to one end of the resistor R1; a sixth node is set at the other end of the resistor R1, and a sixth branch is led out from the sixth node and the capacitor C5 and then grounded.

5. The microcontroller-based synchronous rectification power supply circuit according to claim 4, characterized in that: The resistance of the sampling resistor R2 is 5 milliohms.

6. The microcontroller-based synchronous rectification power supply circuit according to claim 1, characterized in that: The voltage signal acquisition circuit includes: a resistor R3, a resistor R4 and a capacitor C1; The resistor R3 and the resistor R4 are connected in series, a fifth node is set at the connection between the resistor R3 and the resistor R4, a seventh branch is drawn out from the seventh node, connected in series with the capacitor C1, and then connected to the end of the resistor R4 away from R3; the end of the resistor R4 away from R3 is grounded.

7. The microcontroller-based synchronous rectification power supply circuit according to claim 1, characterized in that: The power MOS tube driving circuit adopts a chip of model FD6288.

8. The microcontroller-based synchronous rectification power supply circuit according to claim 1, characterized in that: The microcontroller adopts a 32-bit ARM microprocessor.

9. The microcontroller-based synchronous rectification power supply circuit according to claim 1, characterized in that: The power supply comprises: a power supply input circuit and a voltage reduction circuit; After being connected, the power supply input circuit and the step-down circuit are respectively connected to the microcontroller, the power MOS tube driving circuit, the power conversion circuit, the DC power output circuit, the voltage feedback circuit and the current feedback circuit.

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