DCDC output voltage dynamic regulation circuit based on MCU and DAC regulation

Abstract

The utility model belongs to the field of converter design, and relates to a DCDC output voltage dynamic regulation circuit based on MCU and DAC regulation, which comprises an MCU, a DCDC converter and a control circuit, a pin 14 of the MCU and a pin 8 of the DCDC converter are connected with the control circuit; a pin 14 of the MCU is a pin PA, and a pin 8 of the DCDC converter is a pin FB; the control circuit comprises a first resistor, a triode, a second resistor and a third resistor; the utility model provides a simple, economical and efficient solution which is suitable for cost-sensitive applications. A user can flexibly adjust the output voltage, the requirements of different application scenes are met, and the adaptability of the system is improved. The circuit design is simplified, and complex circuit design and software support are not needed. The implementation is easier, the development difficulty and time cost are reduced, and large-scale production and application are facilitated. The method is not limited by specific application, a universal solution is provided, and the market competitiveness of the product is enhanced.

Description

Technical Field

[0001] The present invention relates to the field of converter design, and in particular to a DCDC output voltage dynamic adjustment circuit based on MCU and DAC control. Background Art

[0002] Traditional DC-DC converter (DCDC) output voltage regulation methods are inflexible, costly, and difficult to procure. Specifically, traditional DCDC chips typically set the output voltage through a fixed feedback resistor (FB). Once set, this method cannot be flexibly adjusted, limiting their use in applications requiring dynamic voltage regulation. Using dedicated chips capable of dynamic voltage regulation often faces issues such as high cost, long procurement cycles, and frequent stock-outs.

[0003] Therefore, how to achieve a low-cost and flexible DCDC output voltage solution is a problem. Utility Model Content

[0004] The purpose of this application is to provide a DCDC output voltage dynamic adjustment circuit based on MCU and DAC control to solve the problems faced by existing DCDC output voltage such as high cost, long procurement cycle, and easy shortage.

[0005] The technical solution of the present application is: a DCDC output voltage dynamic regulation circuit based on MCU and DAC control, comprising an MCU, a DCDC converter and a control circuit; pin 14 of the MCU and pin 8 of the DCDC converter are both connected to the control circuit; pin 14 of the MCU is the PA pin, and pin 8 of the DCDC converter is the FB pin;

[0006] The control circuit includes a first resistor, a transistor, a second resistor and a third resistor; the base of the transistor is connected to pin 14 of the MCU, the collector is connected to pin 8 of the DCDC converter, and the emitter is grounded; one end of the first resistor is connected to the base of the transistor and the other end is grounded; the second resistor is connected in series between the collector of the transistor and pin 8 of the DCDC converter, and one end of the third resistor is connected to pin 8 of the DCDC converter and the other end is grounded.

[0007] Preferably, a fourth resistor is connected in series between the output port of the DCDC converter and the second resistor.

[0008] As a specific implementation method, it includes an MCU, a DCDC converter and a control circuit; the 14th pin of the MCU and the 8th pin of the DCDC converter are both connected to the control circuit; the 14th pin of the MCU is the PA pin, and the 8th pin of the DCDC converter is the FB pin;

[0009] The control circuit includes a first resistor, a MOS transistor, a second resistor, and a third resistor; the gate of the MOS transistor is connected to pin 14 of the MCU, the drain is connected to pin 8 of the DCDC converter, and the source is grounded; one end of the first resistor is connected to the gate of the MOS transistor, and the other end is grounded; the second resistor is connected in series between the drain of the MOS transistor and pin 8 of the DCDC converter; one end of the third resistor is connected to pin 8 of the DCDC converter, and the other end is grounded; the MOS transistor is a P-type MOS transistor.

[0010] Preferably, a fourth resistor is connected in series between the output port of the DCDC converter and the second resistor.

[0011] The DCDC output voltage dynamic adjustment circuit based on MCU and DAC control in this application has the following advantages:

[0012] 1. Provides a simple, economical and efficient solution for cost-sensitive applications.

[0013] 2. Users can flexibly adjust the output voltage to meet the needs of different application scenarios and improve the adaptability of the system.

[0014] 3. Simplified circuit design, no need for complex circuit design and software support. Implementation is easier, reducing development difficulty and time costs, and facilitating large-scale production and application.

[0015] 4. It is not restricted by specific applications and provides a universal solution, which enhances the market competitiveness of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0017] Figure 1 This is the overall circuit structure diagram of this application.

[0018] 1. MCU; 2. DCDC converter; 3. First resistor; 4. Transistor; 5. Second resistor; 6. Third resistor; 7. Fourth resistor. DETAILED DESCRIPTION

[0019] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] A dynamic DC-DC output voltage regulation circuit based on MCU and DAC control includes an MCU1, a DC-DC converter 2, and a control circuit. Pin 14 of MCU1 and pin 8 of DC-DC converter 2 are both connected to the control circuit. Pin 14 of MCU1 is the PA pin, and pin 8 of DC-DC converter 2 is the FB pin. The control circuit includes a first resistor 3, a transistor 4, a second resistor 5, and a third resistor 6. The base of transistor 4 is connected to pin 14 of MCU1, the collector is connected to pin 8 of DC-DC converter 2, and the emitter is grounded. One end of the first resistor 3 is connected to the base of transistor 4 and the other end is grounded to achieve filtering. The second resistor 5 is connected in series between the collector of transistor 4 and pin 8 of DC-DC converter 2. The third resistor 6 has one end connected to pin 8 of DC-DC converter 2 and the other end is grounded. The second resistor 5 and the third resistor 6 together form a resistance conversion circuit.

[0021] DCDC converter 2 is equipped with pull-down equivalent resistors, including RSH and RSL resistors. The output voltage can be adjusted by adjusting the voltage at pin 8. By connecting pin 8 of DCDC converter 2 to transistor 4, transistor 4 can be controlled to enter its linear amplification region. By placing a second resistor 5 at the collector of transistor 4 and connecting it in parallel with a third resistor 6, the total pull-down equivalent resistor value can be changed, thereby changing the pin voltage at pin 8 of DCDC converter 2. This, in turn, adjusts the on / off timing of the power MOSFET switch driver within DCDC converter 2, achieving precise control of the output voltage. By varying the total pull-down equivalent resistor, the voltage at the DCDC chip's FB pin can be flexibly adjusted, thereby enabling flexible regulation of the DCDC output voltage.

[0022] As a specific implementation, the transistor 4 can also be replaced by a MOS tube, specifically a P-type MOS tube, the gate of the MOS tube is connected to pin 14 of the MCU1, the drain is connected to pin 8 of the DCDC converter 2, and the source is grounded, which can achieve the same function as the transistor 4.

[0023] The DCDC converter 2 typically stabilizes the output voltage through a feedback mechanism (FB pin). The voltage on the FB pin has a predetermined proportional relationship with the output voltage, which is determined by a voltage divider resistor network connected to the FB pin.

[0024] When the output voltage changes, the voltage fed back to the FB pin through the voltage divider network will also change accordingly. The comparator inside DCDC converter 2 will compare this voltage with a reference voltage and adjust the duty cycle of its internal switch to maintain a stable output voltage.

[0025] MCU1 uses its DAC function to output a variable analog voltage signal. The range and accuracy of this voltage signal depend on the specific model of MCU1 and the configuration of the DAC. The DAC output voltage signal is used as a control signal to indirectly adjust the output voltage of DCDC converter 2.

[0026] Transistor 4 (such as a BJT or MOSFET) is used as a voltage-controlled current source (VCCS). The DAC output of MCU1 is connected to the base of transistor 4 or the gate of a MOSFET, controlling its conduction current. The collector of transistor 4 (or the drain of a MOSFET) is connected in parallel with the pull-down resistor on the FB pin of DC-DC converter 2. By varying the conduction current of transistor 4 or the MOSFET, the total equivalent resistance in parallel with the FB pin can be dynamically adjusted.

[0027] MCU1's design allows for real-time adjustment of the output voltage, providing a high degree of flexibility and precision while avoiding the inconvenience of hardware component replacement required in traditional methods. When the DAC output of MCU1 changes, the conduction current of transistor 4 or the MOSFET also changes, thereby changing the total equivalent resistance connected in parallel with the FB pin. This change in resistance directly affects the voltage at the FB pin. Since DCDC converter 2 adjusts its output voltage based on the comparison of the FB pin voltage with a reference voltage, changes in the FB pin voltage result in changes in the output voltage. By changing the conduction state of transistor 4 or the MOSFET, the total equivalent value of the pull-down resistor connected to the DCDC voltage regulator feedback pin FB can be dynamically adjusted, thereby adjusting the output voltage of DCDC converter 2.

[0028] By adjusting the output voltage of the DAC, the output voltage of the DCDC converter 2 can be accurately controlled, thereby achieving a free adjustment function of the output power supply.

[0029] Preferably, a fourth resistor 7 is connected in series between the output port of the DCDC converter 2 and the second resistor 5. The output ports of the DCDC converter 2 correspond to pins 1, 15, and 16. By providing the fourth resistor 7, the voltage at pin 8 of the DCDC converter 2 can be effectively controlled, thereby providing voltage stabilization. Specifically, when the voltage output from pin 14 of the MCU 11 is variable from 0V to 3.3V, 4096 different voltage levels can be output. The output voltage range of the DAC depends on the value of the reference voltage (VREF+), where VDD = 3.3V.

[0030] The DAC output voltage can be calculated using the following formula:

[0031] Vout = (DAC value × VREF +) 4096 Vout = 4096 (DAC value × VREF +)

[0032] The DAC value is a digital value ranging from 0 to 4095. The increment is: 3.3V / 4096≈0.000806V

[0033] , which means the minimum output is about 0V and the maximum output is about 3.3.

[0034] In summary, this application has the following advantages:

[0035] 1. Provides a simple, economical and efficient solution for cost-sensitive applications.

[0036] 2. Users can flexibly adjust the output voltage to meet the needs of different application scenarios and improve the adaptability of the system.

[0037] 3. Simplified circuit design, no need for complex circuit design and software support. Implementation is easier, reducing development difficulty and time costs, and facilitating large-scale production and application.

[0038] 4. It is not restricted by specific applications and provides a universal solution, which enhances the market competitiveness of the product.

[0039] Finally, it should be noted that the drawings of the embodiments disclosed in this utility model only involve structures related to the embodiments disclosed in this utility model. Other structures can refer to common designs. In the absence of conflicts, the same embodiment and different embodiments of the utility model can be combined with each other.

[0040] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A DCDC output voltage dynamic adjustment circuit based on MCU and DAC control, characterized by: The invention comprises an MCU (1), a DCDC converter (2) and a control circuit; the 14th pin of the MCU (1) and the 8th pin of the DCDC converter (2) are both connected to the control circuit; the 14th pin of the MCU (1) is a PA pin, and the 8th pin of the DCDC converter (2) is a FB pin; The control circuit comprises a first resistor (3), a transistor (4), a second resistor (5) and a third resistor (6); the base of the transistor (4) is connected to pin 14 of the MCU (1), the collector is connected to pin 8 of the DCDC converter (2), and the emitter is grounded; one end of the first resistor (3) is connected to the base of the transistor (4), and the other end is grounded; the second resistor (5) is connected in series between the collector of the transistor (4) and pin 8 of the DCDC converter (2); one end of the third resistor (6) is connected to pin 8 of the DCDC converter (2), and the other end is grounded.

2. The DCDC output voltage dynamic adjustment circuit based on MCU and DAC control according to claim 1, characterized in that: A fourth resistor (7) is connected in series between the output port of the DCDC converter (2) and the second resistor (5).

3. A DCDC output voltage dynamic adjustment circuit based on MCU and DAC control, characterized by: The invention comprises an MCU (1), a DCDC converter (2) and a control circuit; the 14th pin of the MCU (1) and the 8th pin of the DCDC converter (2) are both connected to the control circuit; the 14th pin of the MCU (1) is a PA pin, and the 8th pin of the DCDC converter (2) is a FB pin; The control circuit comprises a first resistor (3), a MOS tube, a second resistor (5) and a third resistor (6); the gate of the MOS tube is connected to the 14th pin of the MCU (1), the drain is connected to the 8th pin of the DCDC converter (2), and the source is grounded; one end of the first resistor (3) is connected to the gate of the MOS tube, and the other end is grounded; the second resistor (5) is connected in series between the drain of the MOS tube and the 8th pin of the DCDC converter (2); one end of the third resistor (6) is connected to the 8th pin of the DCDC converter (2), and the other end is grounded; the MOS tube is a P-type MOS tube.

4. The DCDC output voltage dynamic adjustment circuit based on MCU and DAC control according to claim 3, characterized in that: A fourth resistor (7) is connected in series between the output port of the DCDC converter (2) and the second resistor (5).

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