Voltage regulation circuit and power supply

Abstract

The utility model discloses a voltage regulation circuit and a power supply, and relates to the technical field of circuits. After the boost-buck converter supplies power, the purpose of changing the output voltage of the output end of the boost-buck converter is achieved after the output voltage of the controller voltage regulating circuit, the voltage of the output end of the boost-buck converter and the first resistor, the second resistor and the third resistor act on a feedback pin of the boost-buck converter; the output voltage of the power adapter is generally smaller than the voltage of the mains supply, so that the potential safety hazard of the adjustable power supply to a human body can be reduced by adjusting the voltage based on the power adapter, a coupling transformer and the like are not needed, and the cost is reduced; and the configuration end of the power adapter is connected with the output end of the power protocol communication processing circuit, so that the power adapter can output relatively high voltage for the boost-buck converter to use, and under the condition of keeping the same power transmission, the high voltage transmission can reduce the magnitude of current, thereby reducing the line and energy loss and improving the transmission efficiency.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit technical field especially relates to a voltage regulating circuit and power supply. BACKGROUND

[0002] With the development of technology, the complexity of various devices and systems is increasing, and higher requirements are put forward for the stability and flexibility of power supply. Traditional fixed voltage power supply cannot meet the diversified demand of modern devices for voltage and current under different working conditions. In this background, adjustable DC regulated power supply becomes an important power supply equipment because it can provide wide range of voltage regulation function to meet the demand of different devices and application scenarios.

[0003] The implementation scheme of the related adjustable DC regulated power supply is that the input 220VAC mains is full-bridge rectified to obtain about 310VDC, the voltage is supplied to the power supply chip through the starting resistor, the power supply chip starts to work to drive the primary winding of the coupled transformer, the induced electromotive force on the secondary winding is full-wave or half-wave rectified to obtain the target DC output, and the set target voltage is divided through the potentiometer and other measures to compare with the fixed threshold voltage to give the power supply chip to adjust the duty cycle of the primary winding to realize voltage regulation. Because the method generally supplies power directly by 220VAC mains, and there is about 310V high voltage DC after full-bridge rectification, which is dangerous, has safety hazards such as electric leakage, and has certain threat to human safety, and because it is supplied by 220VAC mains, it needs coupled transformer, etc., the manufacturing cost is high.

[0004] Therefore, it is an urgent technical problem for those skilled in the art to provide a new adjustable DC regulated power supply to reduce the safety hazards of adjustable power supply to human body and reduce the cost. INVENTION CONTENTS

[0005] The utility model aims at providing a voltage regulating circuit and power supply to solve the technical problems of safety hazards and high cost in the voltage regulation mode of 220VAC mains supply.

[0006] To solve the above technical problems, the utility model provides a voltage regulating circuit, which comprises: a power adapter, a power protocol communication processing circuit, a first voltage stabilizing circuit, a boost-buck converter, a controller voltage regulating circuit, a first resistor, a second resistor, a third resistor and a controller.

[0007] The output end of the power adapter is connected with the input end of the first voltage stabilizing circuit and the power supply end of the boost-buck converter respectively, and the configuration end of the power adapter is connected with the output end of the power protocol communication processing circuit.

[0008] The output terminal of the first voltage regulator circuit is connected to the power supply terminal of the power protocol communication processing circuit and the power supply terminal of the controller, respectively.

[0009] The input terminal of the controller voltage regulation circuit is connected to the first output terminal of the controller;

[0010] The feedback pin of the boost-buck converter is connected to the output terminal of the controller voltage regulation circuit through a first resistor; the feedback pin of the boost-buck converter is connected to the output terminal of the boost-buck converter through a second resistor; the feedback pin of the boost-buck converter is grounded through a third resistor; and the output terminal of the boost-buck converter is connected to the electrical equipment.

[0011] For example, the power protocol communication processing circuit includes a first processor, a fourth resistor, a fifth resistor, and a sixth resistor;

[0012] The first configuration terminal of the first processor is connected to the first terminal of the fifth resistor and the first configuration terminal of the power adapter, respectively; the second configuration terminal of the first processor is connected to the first terminal of the fourth resistor; the first terminal of the sixth resistor and the power supply terminal of the first processor are both connected to the output terminal of the first voltage regulator circuit; the second terminal of the sixth resistor is connected to the third configuration terminal of the first processor; the second terminals of the fourth resistor and the second terminals of the fifth resistor are both grounded.

[0013] For example, it also includes a second voltage regulator circuit; the input terminal of the second voltage regulator circuit is connected to the output terminal of the first voltage regulator circuit;

[0014] The controller voltage regulation circuit includes a first filter circuit and a voltage follower;

[0015] The input terminal of the first filter circuit is connected to the first output terminal of the controller;

[0016] The non-inverting input of the voltage follower is connected to the output of the first filter circuit, and the inverting input of the voltage follower is connected to the output of the voltage follower; the power supply terminal of the voltage follower is connected to the output of the second voltage regulator circuit.

[0017] For example, it also includes: a switch control circuit; the switch control circuit includes a first switch transistor, a second switch transistor, a seventh resistor, and an eighth resistor;

[0018] The first end of the seventh resistor is connected to the gate of the first switching transistor and the drain of the second switching transistor, respectively; the second end of the seventh resistor is connected to the output of the boost-buck converter and the source of the first switching transistor, respectively.

[0019] The gate of the second switch is connected to the second output terminal of the controller and the first terminal of the eighth resistor, respectively. The source of the second switch is grounded, and the drain of the second switch is connected to the gate of the first switch. The source of the first switch is connected to the output terminal of the boost-buck converter, and the drain of the first switch is connected to the load. The second terminal of the eighth resistor is grounded.

[0020] For example, the first voltage regulator circuit includes a second processor, a first capacitor, a second capacitor, a third capacitor, and a ninth resistor;

[0021] The first input terminal of the second processor and the first terminal of the third capacitor are connected, and both are connected to the output terminal of the power adapter. The first output terminal of the second processor is connected to the power supply terminal of the power protocol communication processing circuit and the power supply terminal of the controller, respectively. The second input terminal of the second processor is connected to the first terminal of the ninth resistor, and the second output terminal of the second processor is connected to the first input terminal of the first capacitor.

[0022] The second terminal of the first capacitor and the second terminal of the ninth resistor are both grounded;

[0023] The second terminal of the second capacitor is grounded, and the second terminal of the third capacitor is grounded.

[0024] The second voltage regulator circuit includes a third processor, a fourth capacitor, a fifth capacitor, and a sixth capacitor;

[0025] The input terminal of the third processor and the first terminal of the fourth capacitor are both connected to the output terminal of the first voltage regulator circuit; the second terminal of the fourth capacitor is grounded.

[0026] The output terminal of the third processor is connected to the first terminal of the fifth capacitor and the first terminal of the sixth capacitor, respectively; the second terminals of the fifth capacitor and the sixth capacitor are both grounded.

[0027] Exemplarily, it also includes a current sampling circuit and a voltage sampling circuit;

[0028] The current sampling circuit includes a differential amplifier integrated circuit, a tenth resistor, and a second filter circuit; wherein, the second filter circuit includes an eleventh resistor and a seventh capacitor;

[0029] The power supply terminal of the differential amplifier integrated circuit is connected to the output terminal of the second voltage regulator circuit. The non-inverting input terminal of the differential amplifier integrated circuit is connected to the first terminal of the tenth resistor. The inverting input terminal of the differential amplifier integrated circuit is connected to the second terminal of the tenth resistor and the second terminal of the first switching transistor, respectively. The output terminal of the differential amplifier integrated circuit is connected to the first terminal of the eleventh resistor. The second terminal of the eleventh resistor and the first terminal of the seventh capacitor are both connected to the second input terminal of the controller. The second terminal of the seventh capacitor is grounded.

[0030] The voltage sampling circuit includes a first voltage divider circuit, a voltage protection circuit, and a third filter circuit.

[0031] The first terminal of the first voltage divider circuit is connected to the output terminal of the boost-buck converter;

[0032] The first terminal of the voltage protection circuit is connected to the output terminal of the first voltage regulator circuit.

[0033] The second terminal of the first voltage divider circuit is connected to the second terminal of the voltage protection circuit;

[0034] The third terminal of the voltage protection circuit is connected to the first terminal of the third filter circuit, and the second terminal of the third filter circuit is connected to the first input terminal of the controller.

[0035] The third terminal of the first voltage divider circuit, the fourth terminal of the voltage protection circuit, and the third terminal of the third filter circuit are all grounded.

[0036] For example, it also includes a circuit board temperature sampling circuit; the circuit board temperature sampling circuit includes a second voltage divider circuit and a fourth filter circuit;

[0037] The first terminal of the second voltage divider circuit is connected to the output terminal of the first voltage regulator circuit, the second terminal of the second voltage divider circuit is connected to the first terminal of the fourth filter circuit, and the second terminal of the fourth filter circuit is connected to the third input terminal of the controller; the third terminals of the second voltage divider circuit and the third terminal of the fourth filter circuit are both grounded.

[0038] Exemplarily, it also includes a display circuit and a key circuit;

[0039] The display circuit is connected to the third output terminal of the controller;

[0040] The button circuit is connected to the fourth input terminal of the controller.

[0041] For example, it also includes a cooling fan drive speed control circuit; the cooling fan drive speed control circuit includes an optocoupler, a diode and a fan connector;

[0042] The anode of the optocoupler is connected to the output terminal of the first voltage regulator circuit, the cathode of the optocoupler is connected to the fourth output terminal of the controller, the collector of the optocoupler is connected to the positive terminal of the diode and the second pin of the fan connector, and the emitter of the optocoupler is grounded.

[0043] The negative terminal of the diode and the first pin of the fan connector are both connected to the output terminal of the power adapter.

[0044] To solve the above-mentioned technical problems, this utility model also provides a power supply, including the voltage regulation circuit described above.

[0045] The voltage regulation circuit provided by this utility model includes a power adapter, a power protocol communication processing circuit, a first voltage regulator circuit, a boost-buck converter, a controller voltage regulation circuit, a first resistor, a second resistor, a third resistor, and a controller. First, the power supply terminal of the boost-buck converter is connected to the output terminal of the power adapter, meaning the power adapter supplies power to the boost-buck converter. After the boost-buck converter is powered, since the input terminal of the controller's voltage regulation circuit is connected to the first output terminal of the controller, the feedback pin of the boost-buck converter is connected to the output terminal of the controller's voltage regulation circuit through a first resistor, and the feedback pin of the boost-buck converter is connected to the output terminal of the boost-buck converter through a second resistor. The feedback pin of the boost-buck converter is grounded through a third resistor. Thus, when the output voltage of the controller's voltage regulation circuit, the voltage at the output terminal of the boost-buck converter, and the first, second, and third resistors act on the feedback pin of the boost-buck converter, the output voltage at the output terminal of the boost-buck converter is changed. Second, the output voltage of the power adapter is used as the supply voltage of the boost-buck converter, allowing the boost-buck converter to regulate its voltage based on the output voltage of the power adapter. Since the output voltage of a power adapter is typically lower than the mains voltage, adjusting the voltage using the power adapter reduces the safety hazards of adjustable power supplies to the human body. Furthermore, since no mains power supply is required, coupling transformers are unnecessary, reducing costs. Secondly, by connecting the output of the power adapter to the input of the first voltage regulator circuit, and the output of the first voltage regulator circuit to the power supply terminal of the power protocol communication processing circuit, the voltage output by the first voltage regulator circuit ensures the operation of the power protocol communication processing circuit. Further, the configuration terminal of the power adapter is connected to the output of the power protocol communication processing circuit, allowing the power adapter to output a higher voltage to power the boost-buck converter after the power protocol communication processing circuit is operational. While maintaining the same power transmission, higher voltage transmission reduces current, thereby reducing line loss and energy loss, and improving transmission efficiency.

[0046] In addition, this utility model also provides a power supply, including the voltage regulation circuit mentioned above, which has the same or corresponding technical features as the voltage regulation circuit mentioned above, and has the same effect. Attached Figure Description

[0047] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 A schematic diagram of a voltage regulation circuit provided for an embodiment of this utility model;

[0049] Figure 2 A schematic diagram of a TYPE-C connector provided for an embodiment of this utility model;

[0050] Figure 3 A schematic diagram of a common DC plug provided for an embodiment of this utility model;

[0051] Figure 4 A schematic diagram of a power protocol communication processing circuit provided for an embodiment of this utility model;

[0052] Figure 5 A schematic diagram of a first voltage regulator circuit provided for an embodiment of this utility model;

[0053] Figure 6 A schematic diagram of a second voltage regulator circuit provided for an embodiment of this utility model;

[0054] Figure 7 A schematic diagram of a controller voltage regulation circuit provided for an embodiment of this utility model;

[0055] Figure 8 A schematic diagram of a switch control circuit provided for an embodiment of this utility model;

[0056] Figure 9 A schematic diagram of a current sampling circuit provided for an embodiment of this utility model;

[0057] Figure 10 A schematic diagram of a voltage sampling circuit provided for an embodiment of this utility model;

[0058] Figure 11 A schematic diagram of a circuit board temperature sampling circuit provided for an embodiment of this utility model;

[0059] Figure 12 A schematic diagram of a display circuit provided for an embodiment of this utility model;

[0060] Figure 13 A schematic diagram of a button circuit provided for an embodiment of this utility model;

[0061] Figure 14 A schematic diagram of a cooling fan drive speed control circuit provided for an embodiment of this utility model;

[0062] Figure 15 This is an overall structural diagram of the voltage regulation circuit provided in an embodiment of the present utility model;

[0063] Figure 16 A schematic diagram of the controller in the voltage regulation circuit provided in the embodiment of this utility model. Detailed Implementation

[0064] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0065] The core of this utility model is to provide a voltage regulation circuit and power supply to solve the technical problems of safety hazards and high cost associated with using 220VAC mains power for voltage regulation.

[0066] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Figure 1 A schematic diagram of a voltage regulation circuit provided in an embodiment of this utility model is shown below. Figure 1 As shown, the circuit includes: a power adapter, a power protocol communication processing circuit, a first voltage regulator circuit, a boost-buck converter (BUCK-BOOST), a controller voltage regulation circuit, a first resistor R1, a second resistor R2, a third resistor R3, and a controller.

[0067] The output terminal of the power adapter is connected to the input terminal of the first voltage regulator circuit and the power supply terminal of the boost-buck converter, respectively, and the configuration terminal of the power adapter is connected to the output terminal of the power protocol communication processing circuit.

[0068] The output terminal of the first voltage regulator circuit is connected to the power supply terminal of the power protocol communication processing circuit and the power supply terminal of the controller, respectively.

[0069] The input terminal of the controller voltage regulation circuit is connected to the first output terminal of the controller;

[0070] The feedback pin (FB pin) of the boost-buck converter is connected to the output terminal (Vdac) of the controller voltage regulation circuit through the first resistor R1. The feedback pin of the boost-buck converter is connected to the output terminal (VOUT) of the boost-buck converter through the second resistor R2. The feedback pin of the boost-buck converter is grounded through the third resistor R3. The output terminal of the boost-buck converter is connected to the electrical equipment.

[0071] A power adapter includes a fast charger and a connector. Power adapters can be used for various electronic products, such as mobile phone adapters. Figure 2 This is a schematic diagram of a TYPE-C connector provided in an embodiment of the present invention. The TYPE-C connector J1 is used to connect a mobile phone fast charger and has pins VBUS for providing power, configuration terminal CC1, and configuration terminal CC2. Figure 3 This diagram illustrates a common DC plug used in embodiments of the present invention, which meets power supply requirements in various scenarios. The TYPE-C or DC plug connector is primarily used for connecting mobile phone PD fast chargers or other non-adjustable DC power supplies, providing power to this design.

[0072] The power protocol communication processing circuit simulates the PD protocol to adjust the output voltage of the power adapter (such as the output voltage of a mobile phone PD fast charger) to 20V, thereby increasing the maximum power of this design. Figure 4 A schematic diagram of a power protocol communication processing circuit provided for an embodiment of this utility model is shown below. Figure 4 As shown, the power protocol communication processing circuit includes a first processor U1, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6.

[0073] The first configuration terminal CC1 of the first processor U1 is connected to the first terminal of the fifth resistor R5 and the first configuration terminal CC1 of the power adapter, respectively; the second configuration terminal CC2 of the first processor U1 is connected to the first terminal of the fourth resistor R4; the first terminal of the sixth resistor R6 and the power supply terminal VDD of the first processor U1 are both connected to the output terminal of the first voltage regulator circuit; the second terminal of the sixth resistor R6 is connected to the third configuration terminal CFG of the first processor U1; the second terminals of the fourth resistor R4 and the second terminals of the fifth resistor R5 are both grounded.

[0074] The first processor U1 can be a PD decoy (PD decoy chip). The first processor U1 can trick a PD-compliant mobile phone fast charger into outputting 20V. The sixth resistor R6 is the configuration pin for decoy fast charger output voltage. The fourth resistor R4 and the fifth resistor R5 ensure the fast charger can output 5V DC before successful decoy, allowing the first processor U1 to function normally. The third configuration pin CFG of the first processor U1 is connected to the power supply pin VDD of the first processor U1 via the sixth resistor R6. Different resistance values ​​of the sixth resistor R6 correspond to different voltage request levels. Table 1 shows the correspondence between resistors and requested voltages.

[0075] Table 1

[0076]

[0077] The first voltage regulator circuit (Low Dropout Regulator (LDO) -3.3V) is used to produce a stable 3.3V voltage to power loads such as the controller and power protocol communication processing circuits. The first voltage regulator circuit supports high voltage input. Figure 5 A schematic diagram of a first voltage regulator circuit provided for an embodiment of this utility model is shown below. Figure 5 As shown, the first voltage regulator circuit includes a second processor U2, a first capacitor C1, a second capacitor C2, a third capacitor C3, and a ninth resistor R9.

[0078] The first input terminal of the second processor U2 and the first terminal of the third capacitor C3 are connected, and both are connected to the output terminal VBUS of the power adapter. The first output terminal (output 3.3V) of the second processor U2 is connected to the power supply terminal of the power protocol communication processing circuit and the power supply terminal of the controller, respectively. The second input terminal of the second processor U2 is connected to the first terminal of the ninth resistor R9. The second output terminal of the second processor U2 is connected to the first input terminal of the first capacitor C1.

[0079] The second terminal of the first capacitor C1 and the second terminal of the ninth resistor R9 are both grounded;

[0080] The second terminal of the second capacitor C2 is grounded, and the second terminal of the third capacitor C3 is grounded.

[0081] In addition to the first voltage regulator circuit for producing a stable 3.3V, the voltage regulation circuit also includes a second voltage regulator circuit (LDO-1.8V) to adjust the 3.3V power supply to a lower-noise 1.8V power supply to power the subsequent operational amplifier. Figure 6 A schematic diagram of a second voltage regulator circuit provided for an embodiment of this utility model is shown below. Figure 6 As shown, the input terminal (receives 3.3V) of the second voltage regulator circuit is connected to the output terminal (outputs 3.3V) of the first voltage regulator circuit.

[0082] The second voltage regulator circuit includes a third processor U3, a fourth capacitor C4, a fifth capacitor C5, and a sixth capacitor C6.

[0083] The input terminal of the third processor U3 and the first terminal of the fourth capacitor C4 are both connected to the output terminal of the first voltage regulator circuit; the second terminal of the fourth capacitor C4 is grounded.

[0084] The output terminal of the third processor U3 is connected to the first terminal of the fifth capacitor C5 and the first terminal of the sixth capacitor C6, respectively; the second terminal of the fifth capacitor C5 and the second terminal of the sixth capacitor C6 are both grounded.

[0085] Figure 7 A schematic diagram of a controller voltage regulation circuit provided for an embodiment of this utility model is shown below. Figure 7 As shown, the controller voltage regulation circuit includes a first filter circuit and a voltage follower U4;

[0086] The input terminal of the first filter circuit is connected to the first output terminal (PWM_DAC) of the controller;

[0087] The non-inverting input of voltage follower U4 is connected to the output of the first filter circuit, and the inverting input of voltage follower U4 is connected to the output of voltage follower U4; the power supply terminal of voltage follower U4 is connected to the output (1.8V) of the second voltage regulator circuit.

[0088] The function of the boost-buck converter is to regulate the 20V output power supply to the target output voltage value set by the controller. Since the voltage regulation of the boost-buck converter is achieved through the FB pin, when the voltage on the FB pin is greater than 1.2V, the converter adjusts the duty cycle of the internal Metal-Oxide-Semiconductor Field-Effect Transistor (MOS) to reduce the output voltage, causing the FB voltage to decrease synchronously until it reaches 1.2V. At this point, voltage regulation can only be achieved by adjusting the voltage on the FB pin. The controller output PWM is passed through two cascaded LC low-pass filters to obtain the DC component, which is then passed through a voltage follower U4 to improve the driving capability before being input to the controller's ADC for sampling, forming a closed-loop control. Therefore, the output voltage Vdac of the controller's voltage regulation circuit can be obtained by adjusting the duty cycle of the controller's PWM output. This method utilizes PWM to achieve analog DAC output. The obtained Vdac is input to the first resistor R1 and applied to the FB pin. According to the principle of power supply superposition, the output voltage value of the entire product can be obtained. The formula for calculating the output voltage is:

[0089] .

[0090] The voltage regulation circuit also includes a switching control circuit. The switching control circuit can disconnect the output voltage from the external load, so as to eliminate the fault source in scenarios such as output overcurrent caused by load short circuit. Figure 8 A schematic diagram of a switch control circuit provided in an embodiment of this utility model is shown below. Figure 8 As shown, the switch control circuit includes a first switch Q1, a second switch Q2, a seventh resistor R7, and an eighth resistor R8.

[0091] The first end of the seventh resistor R7 is connected to the gate of the first switching transistor Q1 and the drain of the second switching transistor Q2, respectively; the second end of the seventh resistor R7 is connected to the output terminal (VOUT) of the boost-buck converter and the source of the first switching transistor Q1, respectively.

[0092] The gate of the second switch Q2 is connected to the second output terminal (PWR_ON_OFF) of the controller and the first terminal of the eighth resistor R8, respectively. The source of the second switch Q2 is grounded, and the drain of the second switch Q2 is connected to the gate of the first switch Q1. The source of the first switch Q1 is connected to the output terminal (VOUT) of the boost-buck converter, and the drain of the first switch Q1 is connected to the load. The second terminal of the eighth resistor R8 is grounded. The first switch Q1 is a PMOS transistor, and the second switch Q2 is an NMOS transistor. The seventh resistor R7 and the eighth resistor R8 are bias resistors to prevent false turn-on caused by a floating gate.

[0093] The voltage regulation circuit also includes a current sampling circuit and a voltage sampling circuit. Figure 9 A schematic diagram of a current sampling circuit provided in an embodiment of this utility model is shown below. Figure 9 As shown, the current sampling circuit includes a differential amplifier integrated circuit U5, a tenth resistor R10, and a second filter circuit; wherein, the second filter circuit includes an eleventh resistor R11 and a seventh capacitor C7.

[0094] The power supply terminal of the differential amplifier integrated circuit U5 is connected to the output terminal of the second voltage regulator circuit. The non-inverting input terminal of the differential amplifier integrated circuit U5 is connected to the first terminal of the tenth resistor R10. The inverting input terminal of the differential amplifier integrated circuit U5 is connected to the second terminal of the tenth resistor R10 and the second terminal of the first switching transistor Q1, respectively. The output terminal of the differential amplifier integrated circuit U5 is connected to the first terminal of the eleventh resistor R11. The second terminal of the eleventh resistor R11 and the first terminal of the seventh capacitor C7 are both connected to the second input terminal (ADC_CURRENT) of the controller. The second terminal of the seventh capacitor C7 is grounded. In the current sampling circuit, which consists of the differential amplifier integrated circuit U5, the sampling resistor R11, and a first-order RC low-pass filter (the circuit composed of the second terminal of the eleventh resistor R11 and the seventh capacitor C7), the differential voltage value is amplified and input to the ADC analog-to-digital conversion pin of the controller to complete the sampling of the analog voltage.

[0095] Figure 10 A schematic diagram of a voltage sampling circuit provided for an embodiment of this utility model is shown below. Figure 10 As shown, the voltage sampling circuit includes a first voltage divider circuit, a voltage protection circuit, and a third filter circuit;

[0096] The first terminal of the first voltage divider circuit is connected to the output terminal VOUT of the boost-buck converter.

[0097] The first terminal of the voltage protection circuit is connected to the output terminal of the first voltage regulator circuit;

[0098] The second terminal of the first voltage divider circuit is connected to the second terminal of the voltage protection circuit;

[0099] The third terminal of the voltage protection circuit is connected to the first terminal of the third filter circuit, and the second terminal of the third filter circuit is connected to the first input terminal (ADC_OUT_V) of the controller.

[0100] The third terminal of the first voltage divider circuit, the fourth terminal of the voltage protection circuit, and the third terminal of the third filter circuit are all grounded.

[0101] Figure 10 In the first voltage divider circuit, there are twelfth resistor R12 and thirteenth resistor R13. The voltage protection circuit includes a first clamping diode D1 and a second clamping diode D2. The third filter circuit includes a fourteenth resistor R14 and an eighth capacitor C8. The voltage sampling circuit consists of voltage divider resistors R12 and R13 and a first-order RC low-pass filter (fourteenth resistor R14 and eighth capacitor C8). It divides the output voltage value and inputs it to the controller's ADC analog-to-digital conversion pin to complete the analog voltage sampling. The first clamping diode D1 and the second clamping diode D2 prevent the output voltage from being too high, which would cause the voltage after voltage division to exceed 3.3V and damage the controller.

[0102] The voltage regulation circuit also includes a circuit board temperature sampling circuit. This circuit collects the circuit board temperature to prevent overheating damage. Figure 11 A schematic diagram of a circuit board temperature sampling circuit provided for an embodiment of this utility model is shown below. Figure 11 As shown, the circuit board temperature sampling circuit includes a second voltage divider circuit and a fourth filter circuit;

[0103] The first terminal of the second voltage divider circuit is connected to the output terminal of the first voltage regulator circuit. The second terminal of the second voltage divider circuit is connected to the first terminal of the fourth filter circuit. The second terminal of the fourth filter circuit is connected to the third input terminal (ADC_TEMP) of the controller. The third terminals of the second voltage divider circuit and the third terminal of the fourth filter circuit are both grounded.

[0104] Figure 11In the circuit, the second voltage divider circuit includes a fifteenth resistor R15 and a sixteenth resistor R16, with the sixteenth resistor R16 being a negative temperature coefficient thermistor. The fourth filter circuit includes a seventeenth resistor R17 and a ninth capacitor C9. After the voltage is divided by the fifteenth resistor R15 and the sixteenth resistor R16, it passes through a first-order low-pass filter (the filter composed of the seventeenth resistor R17 and the ninth capacitor C9) to input the voltage value to the ADC analog-to-digital converter pin of the controller to complete the analog voltage sampling. Finally, the temperature value is calculated by the program.

[0105] The voltage regulation circuit also includes a display circuit and a keypad circuit;

[0106] The display circuit is connected to the third output terminal (IIC interface) of the controller;

[0107] The button circuit is connected to the fourth input terminal (KEY1, KEY2) of the controller.

[0108] Figure 12 A schematic diagram of a display circuit provided for an embodiment of this utility model is shown below. Figure 12 As shown, the OLED display circuit is driven by IIC protocol communication and is used to display information such as voltage, current and temperature collected. Figure 13 A schematic diagram of a button circuit provided for an embodiment of this utility model is shown below. Figure 13 As shown, the button circuit consists of a button switch. The program can control the integrated pull-up resistor, so it is only necessary to detect the state of the input / output (IO) to realize button detection. Button debouncing can be achieved in the program through delay, so no hardware debouncing circuit is added here.

[0109] The voltage regulation circuit also includes a cooling fan drive speed control circuit. Figure 14 A schematic diagram of a cooling fan drive speed control circuit provided in an embodiment of this utility model is shown below. Figure 14 As shown, the cooling fan drive speed control circuit includes an optocoupler U6, a diode D3, and a fan connector H1;

[0110] The anode of optocoupler U6 is connected to the output terminal (3.3V) of the first voltage regulator circuit, the cathode of optocoupler U6 is connected to the fourth output terminal (FAN_PWM) of the controller, the collector of optocoupler U6 is connected to the positive terminal of diode D3 and the second pin of fan connector H1 respectively, and the emitter of optocoupler U6 is grounded.

[0111] The cathode of diode D3 and the first pin of fan connector H1 are both connected to the output terminal VBUS of the power adapter. When the controller detects that the circuit board temperature is too high, it can output PWM with different duty cycles to drive the fan to achieve physical cooling. The optocoupler U6 is used to electrically isolate the 3.3V and 20V voltages. The resistance between the anode of optocoupler U6 and the output terminal (3.3V) of the first voltage regulator circuit is the current limiting resistor of the light-emitting diode. Since the fan is an inductive load, a return path is required when it is turned off, and diode D3 is the freewheeling diode of the fan.

[0112] To enable those skilled in the art to better understand the voltage regulation circuit of this utility model, Figure 15 The overall structural diagram of the voltage regulation circuit provided in the embodiment of this utility model is as follows: Figure 15 As shown, the descriptions of each module are as follows:

[0113] TYPE-C or DC plug connector: mainly used for connecting mobile phone PD fast chargers or other non-adjustable DC power supplies to provide power to this design.

[0114] PD decoy: Simulates the PD protocol to adjust the output voltage of the mobile phone PD fast charger to 20V, thereby increasing the maximum power of this design.

[0115] BUCK-BOOST converter: Adjusts the 20V output power supply to the target output voltage value set by the controller.

[0116] LDO-3.3V: Used to produce a stable 3.3V power supply for controllers, etc.

[0117] LDO-1.8V: Primarily adjusts the 3.3V power supply to a lower-noise 1.8V power supply to power the subsequent operational amplifier.

[0118] MCU (Controller): Primarily processes various parameters collected by the system, allows users to set output voltage, current, and other parameters, and performs other controls.

[0119] Output voltage VOUT ADC: The controller collects the output voltage and compares it with the user-set value. When they are inconsistent, it is easy to adjust the output voltage.

[0120] Output current sampling ADC: The output current passes through the sampling resistor to obtain a differential voltage. After passing through the differential circuit, the controller collects the voltage and internally converts it into a current value for comparison with the user-set value. When there is an overcurrent, it is easy to shut down the output to protect the entire system.

[0121] Onboard thermistor ADC: Collects circuit board temperature to prevent overheating damage.

[0122] PWM DAC voltage regulation circuit: outputs the user-set voltage value to the boost-buck converter to achieve voltage regulation function.

[0123] Cooling fan drive circuit: When the circuit board is detected to be overheating, the fan is driven to cool it down and prevent damage.

[0124] OLED display: The various parameters collected by the controller are output to the user through the display screen.

[0125] Keypad input circuit: Users input the desired output voltage, current and other parameters via keypad input.

[0126] Output voltage switching control circuit: The output voltage can be disconnected from the external load so that the fault source can be cut off in scenarios such as output overcurrent caused by load short circuit.

[0127] Figure 16 A schematic diagram of the controller in the voltage regulation circuit provided in the embodiment of this utility model is shown below. Figure 16 As shown, the controller includes multiple input and output terminals as described above. It has a built-in power-on reset circuit and uses a high-precision RC oscillation circuit, eliminating the need for an external crystal oscillator and reset circuit. It can be used immediately upon power-on and has a built-in e²PROM for storing user-set parameter values.

[0128] The voltage regulation circuit achieves voltage regulation as follows:

[0129] 1. When the mobile phone PD fast charger supplies power to this design, the power protocol communication processing circuit is not working. The TYPE-C outputs 5V to the LDO, and the LDO outputs 3.3V to supply power to the decoy. At this time, the decoy chip works normally and adjusts the TYPE-C voltage to 20V to supply the boost-buck converter.

[0130] 2. After the LDO outputs 3.3V to power the controller, the controller starts to work normally. The controller reads the voltage value set by the user from the built-in e²PROM and outputs it to the boost-buck converter through PWM DAC technology. The converter adjusts the output voltage internally. When the controller detects that the output voltage is consistent with the user-set voltage through the ADC, it opens the output voltage switch to output power to the outside.

[0131] 3. When a load current passes through the current sampling resistor, the differential voltage across the resistor is input to a first-order low-pass filter through a differential amplifier circuit and then output to the controller. The controller converts the collected voltage value into the output current and displays it on the OLED screen for the user's reference. When the output current exceeds the current set by the user, the controller will control the output voltage switch to cut off the output path.

[0132] 4. The controller synchronously collects the circuit board temperature and compares it with the user-set temperature threshold. When the temperature is too high, it controls the cooling fan to turn on to cool the circuit board.

[0133] This voltage regulation circuit has the following advantages:

[0134] 1. The circuit enables the mobile phone PD fast charger to output 20V, which is then converted into an adjustable DC regulated power supply via a boost-buck converter;

[0135] 2. It uses common mobile phone fast chargers as the power supply, so the overall production cost is low, the size is small, the weight is light, and the mobile phone fast charging power can reach up to about 200W, which can meet the daily needs of electronic enthusiasts; it uses common mobile phone fast chargers and other necessities as the power supply, so the overall production cost is low, the size is small, the weight is light and easy to carry, avoiding the disadvantage of traditional DC regulated power supplies being inconvenient to carry.

[0136] 3. This design outputs 20V low-voltage DC power from a mobile phone charger, not the approximately 310V high-voltage DC power from the mains or after full-bridge rectification. Since the safe voltage for the human body is 36V, this design poses no safety hazard to the human body.

[0137] 4. The closed-loop control of the DAC output is achieved by using the simple and highly operable PWM technology, which replaces the traditional method of using DAC chips and reduces costs.

[0138] The voltage regulation circuit has been described above. This embodiment also provides a power supply, including the voltage regulation circuit described above. The embodiments of the voltage regulation circuit have been described in detail above, and the embodiments of the power supply will not be repeated here, but have the same beneficial effects as the voltage regulation circuit mentioned above.

[0139] The voltage regulation circuit and power supply provided by this utility model have been described in detail above. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. It should be noted that those skilled in the art can make various improvements and modifications to this utility model without departing from its principles, and these improvements and modifications also fall within the protection scope of this utility model.

[0140] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A voltage regulation circuit, characterized in that, include: The power adapter, power protocol communication processing circuit, first voltage regulator circuit, boost-buck converter, controller voltage regulation circuit, first resistor, second resistor, third resistor and controller; The output terminal of the power adapter is connected to the input terminal of the first voltage regulator circuit and the power supply terminal of the boost-buck converter, respectively, and the configuration terminal of the power adapter is connected to the output terminal of the power protocol communication processing circuit. The output terminal of the first voltage regulator circuit is connected to the power supply terminal of the power protocol communication processing circuit and the power supply terminal of the controller, respectively. The input terminal of the controller voltage regulation circuit is connected to the first output terminal of the controller; The feedback pin of the boost-buck converter is connected to the output terminal of the controller voltage regulation circuit through a first resistor; the feedback pin of the boost-buck converter is connected to the output terminal of the boost-buck converter through a second resistor; the feedback pin of the boost-buck converter is grounded through a third resistor; and the output terminal of the boost-buck converter is connected to the electrical equipment.

2. The voltage regulation circuit according to claim 1, characterized in that, The power protocol communication processing circuit includes a first processor, a fourth resistor, a fifth resistor, and a sixth resistor; The first configuration terminal of the first processor is connected to the first terminal of the fifth resistor and the first configuration terminal of the power adapter, respectively; the second configuration terminal of the first processor is connected to the first terminal of the fourth resistor; the first terminal of the sixth resistor and the power supply terminal of the first processor are both connected to the output terminal of the first voltage regulator circuit; the second terminal of the sixth resistor is connected to the third configuration terminal of the first processor; the second terminals of the fourth resistor and the second terminals of the fifth resistor are both grounded.

3. The voltage regulation circuit according to claim 1 or 2, characterized in that, It also includes a second voltage regulator circuit; the input terminal of the second voltage regulator circuit is connected to the output terminal of the first voltage regulator circuit. The controller voltage regulation circuit includes a first filter circuit and a voltage follower; The input terminal of the first filter circuit is connected to the first output terminal of the controller; The non-inverting input of the voltage follower is connected to the output of the first filter circuit, and the inverting input of the voltage follower is connected to the output of the voltage follower; the power supply terminal of the voltage follower is connected to the output of the second voltage regulator circuit.

4. The voltage regulation circuit according to claim 3, characterized in that, Also includes: A switch control circuit; the switch control circuit includes a first switch transistor, a second switch transistor, a seventh resistor, and an eighth resistor; The first end of the seventh resistor is connected to the gate of the first switching transistor and the drain of the second switching transistor, respectively; the second end of the seventh resistor is connected to the output of the boost-buck converter and the source of the first switching transistor, respectively. The gate of the second switch is connected to the second output terminal of the controller and the first terminal of the eighth resistor, respectively. The source of the second switch is grounded, and the drain of the second switch is connected to the gate of the first switch. The source of the first switch is connected to the output terminal of the boost-buck converter, and the drain of the first switch is connected to the load. The second terminal of the eighth resistor is grounded.

5. The voltage regulation circuit according to claim 3, characterized in that, The first voltage regulator circuit includes a second processor, a first capacitor, a second capacitor, a third capacitor, and a ninth resistor; The first input terminal of the second processor and the first terminal of the third capacitor are connected, and both are connected to the output terminal of the power adapter. The first output terminal of the second processor is connected to the power supply terminal of the power protocol communication processing circuit and the power supply terminal of the controller, respectively. The second input terminal of the second processor is connected to the first terminal of the ninth resistor, and the second output terminal of the second processor is connected to the first input terminal of the first capacitor. The second terminal of the first capacitor and the second terminal of the ninth resistor are both grounded; The second terminal of the second capacitor is grounded, and the second terminal of the third capacitor is grounded. The second voltage regulator circuit includes a third processor, a fourth capacitor, a fifth capacitor, and a sixth capacitor; The input terminal of the third processor and the first terminal of the fourth capacitor are both connected to the output terminal of the first voltage regulator circuit; the second terminal of the fourth capacitor is grounded. The output terminal of the third processor is connected to the first terminal of the fifth capacitor and the first terminal of the sixth capacitor, respectively; the second terminals of the fifth capacitor and the sixth capacitor are both grounded.

6. The voltage regulation circuit according to claim 4, characterized in that, It also includes current sampling circuits and voltage sampling circuits; The current sampling circuit includes a differential amplifier integrated circuit, a tenth resistor, and a second filter circuit; wherein, the second filter circuit includes an eleventh resistor and a seventh capacitor; The power supply terminal of the differential amplifier integrated circuit is connected to the output terminal of the second voltage regulator circuit. The non-inverting input terminal of the differential amplifier integrated circuit is connected to the first terminal of the tenth resistor. The inverting input terminal of the differential amplifier integrated circuit is connected to the second terminal of the tenth resistor and the second terminal of the first switching transistor, respectively. The output terminal of the differential amplifier integrated circuit is connected to the first terminal of the eleventh resistor. The second terminal of the eleventh resistor and the first terminal of the seventh capacitor are both connected to the second input terminal of the controller. The second terminal of the seventh capacitor is grounded. The voltage sampling circuit includes a first voltage divider circuit, a voltage protection circuit, and a third filter circuit. The first terminal of the first voltage divider circuit is connected to the output terminal of the boost-buck converter; The first terminal of the voltage protection circuit is connected to the output terminal of the first voltage regulator circuit. The second terminal of the first voltage divider circuit is connected to the second terminal of the voltage protection circuit; The third terminal of the voltage protection circuit is connected to the first terminal of the third filter circuit, and the second terminal of the third filter circuit is connected to the first input terminal of the controller. The third terminal of the first voltage divider circuit, the fourth terminal of the voltage protection circuit, and the third terminal of the third filter circuit are all grounded.

7. The voltage regulation circuit according to claim 3, characterized in that, It also includes a circuit board temperature sampling circuit; the circuit board temperature sampling circuit includes a second voltage divider circuit and a fourth filter circuit. The first terminal of the second voltage divider circuit is connected to the output terminal of the first voltage regulator circuit, the second terminal of the second voltage divider circuit is connected to the first terminal of the fourth filter circuit, and the second terminal of the fourth filter circuit is connected to the third input terminal of the controller; the third terminals of the second voltage divider circuit and the third terminal of the fourth filter circuit are both grounded.

8. The voltage regulation circuit according to claim 3, characterized in that, It also includes display circuitry and keypad circuitry; The display circuit is connected to the third output terminal of the controller; The button circuit is connected to the fourth input terminal of the controller.

9. The voltage regulation circuit according to claim 3, characterized in that, It also includes a cooling fan drive speed control circuit; the cooling fan drive speed control circuit includes an optocoupler, a diode, and a fan connector; The anode of the optocoupler is connected to the output terminal of the first voltage regulator circuit, the cathode of the optocoupler is connected to the fourth output terminal of the controller, the collector of the optocoupler is connected to the positive terminal of the diode and the second pin of the fan connector, and the emitter of the optocoupler is grounded. The negative terminal of the diode and the first pin of the fan connector are both connected to the output terminal of the power adapter.

10. A power supply, characterized in that, Includes the voltage regulation circuit as described in any one of claims 1 to 9.

Images