Low-noise high-power adjustable step-down circuit

Abstract

The utility model discloses a low-noise high-power adjustable step-down circuit, which relates to the field of voltage conversion and comprises a current supply module, a multi-branch output module, a voltage conversion module and a control module, the multi-branch output module is used for outputting voltage and current through a plurality of branches, reducing the power consumption of a single branch and improving the output current; the output voltage adjusting module is used for changing the magnitude of the conduction current provided by the current providing module by changing circuit impedance, further adjusting the magnitude of the current of a single branch in the multi-branch output module, and finally changing the magnitude of the output voltage; compared with the prior art, the beneficial effects of the utility model are that through the design of the multi-branch output module, the input range and the loading capacity of a product are improved, and the application range is wide; by designing an output voltage adjusting module, the magnitude of output voltage can be adjusted; a reverse protection module is designed, reverse protection is achieved, no burning risk exists, and product safety is improved.

Description

Technical Field

[0001] This utility model relates to the field of voltage conversion, specifically a low-noise, high-power adjustable step-down circuit. Background Technology

[0002] LDO (Low Dropout Regulator) step-down chips achieve stable output by linearly adjusting the voltage difference between the input and output voltages. They feature low dropout voltage (hundreds of millivolts), low noise, and high ripple suppression, making them suitable for precision electronic power supply applications.

[0003] Integrated LDO step-down chips, such as the 7805 series and LD1085 series, have a rated current of no more than 3A and an input voltage range of less than 36V. They are designed for low-dropout applications and are limited in high-voltage or high-current applications, thus having a narrow range of applications and requiring improvement. Utility Model Content

[0004] The purpose of this invention is to provide a low-noise, high-power adjustable step-down circuit to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A low-noise, high-power adjustable step-down circuit includes:

[0007] A current supply module is used to provide conduction current to the multi-branch output module;

[0008] Multi-branch output module is used to output voltage and current through multiple branches, thereby reducing the power consumption of a single branch and increasing the output current;

[0009] The output voltage regulation module is used to change the magnitude of the conduction current provided by the current supply module by changing the circuit impedance, thereby adjusting the current magnitude of a single branch in the multi-branch output module, and ultimately changing the output voltage magnitude.

[0010] The current supply module connects to multiple branch output modules and the output voltage regulation module.

[0011] As a further embodiment of this utility model: the current supply module includes a resistor R5, a transistor Q3, and a resistor R6. One end of the resistor R5 is connected to the positive input voltage +VIN and the collector of the transistor Q3. The other end of the resistor R5 is connected to the base of the transistor Q3 and the output voltage adjustment module. The emitter of the transistor Q3 is connected to one end of the resistor R6, and the other end of the resistor R6 is connected to the multi-branch output module.

[0012] As a further embodiment of this utility model: the multi-branch output module includes multiple branches connected in parallel. Each branch includes a transistor Q1 and a resistor R1. The collector of transistor Q1 is connected to the positive input voltage +VIN, the base of transistor Q1 is connected to the current supply module, and the emitter of transistor Q1 is connected to the positive output voltage +V0.

[0013] As a further improvement of this utility model: the output voltage regulation module includes transistors Q4 and Q5. The collector of transistor Q4 is connected to the current supply module, the collector of transistor Q5 is connected to the collector of transistor Q4, the emitter of transistor Q4 is connected to the negative input voltage -VIN, the emitter of transistor Q5 is connected to the negative output voltage -V0 through resistor R23, the base of transistor Q4 is connected to the output terminal of amplifier IC5-A through resistor R12, the non-inverting input of amplifier IC5-A is connected to one end of resistor R11, the other end of resistor R11 is connected to one end of resistor R4 and one end of potentiometer R8, the other end of resistor R4 is connected to the positive output voltage +V0, and the potentiometer... The other end of R8 is connected to the negative input voltage -VIN. The inverting input of amplifier IC5-A is connected to one end of resistor R13. The other end of resistor R13 is connected to the reference voltage VREF and one end of resistor R15. The other end of resistor R15 is connected to one end of resistor R17 and one end of resistor R18. The other end of resistor R17 is connected to the negative input voltage -VIN. The other end of resistor R18 is connected to the inverting input of amplifier IC5-B. The non-inverting input of amplifier IC5-B is connected to the negative output voltage -V0 through resistor R20. The output of amplifier IC5-B is connected to one end of resistor R19. The other end of resistor R19 is connected to the base of transistor Q5.

[0014] As a further improvement of this utility model, the low-noise, high-power adjustable step-down circuit also includes:

[0015] The reverse protection module is used to ensure that the control circuit is open when the power supply is connected in the correct direction and closed when the power supply is connected in the reverse direction.

[0016] The reverse protection module includes resistor R16, MOSFET M1, resistor R22, diode D1, and capacitor C6. One end of resistor R16 is connected to the positive input voltage +VIN, and the other end of resistor R16 is connected to the gate of MOSFET M1, one end of resistor R22, the negative terminal of diode D1, and one end of capacitor C6. The drain of MOSFET M1 is connected to the negative input voltage -VIN, and the source of MOSFET M1 is connected to the other end of resistor R22, the positive terminal of diode D1, and the other end of capacitor C6.

[0017] As a further improvement of this utility model, the low-noise, high-power adjustable step-down circuit also includes:

[0018] The series voltage regulator module is used to obtain the operating voltage of the output voltage regulation module;

[0019] The series voltage regulator module includes resistors R3 and R7, transistor Q6, three-terminal regulator IC4, resistors R9 and R10, and capacitor C2. One end of resistor R3 is connected to the positive terminal of the input voltage +VIN, and the other end of resistor R3 is connected to one end of resistor R7 and the collector of transistor Q6. The emitter of transistor Q6 is connected to the voltage regulation module (the output operating voltage VCC is connected to the voltage regulation module). One end of resistor R10 is connected to the base of transistor Q6 and the negative terminal of three-terminal regulator IC4. The other end of resistor R7 is connected to the positive terminal of three-terminal regulator IC4 and the negative terminal of the input voltage -VIN. One end of resistor R9 and one end of capacitor C2 are connected to the other end of resistor R10, the other end of capacitor C2, the reference voltage VREF (2.5V), and the reference terminal of three-terminal regulator IC4.

[0020] Compared with the prior art, the beneficial effects of this utility model are: by designing a multi-branch output module, this utility model improves the product's input range and load capacity, making it widely applicable; by designing an output voltage adjustment module, the output voltage can be adjusted; and by designing a reverse protection module, it has anti-reverse protection, eliminates the risk of burnout, and improves product safety. Attached Figure Description

[0021] Figure 1 This is a circuit diagram of a low-noise, high-power adjustable step-down circuit. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0023] Please see Figure 1 A low-noise, high-power adjustable step-down circuit includes:

[0024] A current supply module is used to provide conduction current to the multi-branch output module;

[0025] Multi-branch output module is used to output voltage and current through multiple branches, thereby reducing the power consumption of a single branch and increasing the output current;

[0026] The output voltage regulation module is used to change the magnitude of the conduction current provided by the current supply module by changing the circuit impedance, thereby adjusting the current magnitude of a single branch in the multi-branch output module, and ultimately changing the output voltage magnitude.

[0027] The current supply module connects to multiple branch output modules and the output voltage regulation module.

[0028] In this embodiment: Please refer to Figure 1 The current supply module includes resistor R5, transistor Q3, and resistor R6. One end of resistor R5 is connected to the positive input voltage +VIN and the collector of transistor Q3. The other end of resistor R5 is connected to the base of transistor Q3 and the output voltage adjustment module. The emitter of transistor Q3 is connected to one end of resistor R6, and the other end of resistor R6 is connected to the multi-branch output module.

[0029] In this embodiment: Please refer to Figure 1 The multi-branch output module includes multiple branches connected in parallel. Each branch includes a transistor Q1 and a resistor R1. The collector of transistor Q1 is connected to the positive input voltage +VIN, the base of transistor Q1 is connected to the current supply module, and the emitter of transistor Q1 is connected to the positive output voltage +V0.

[0030] In this embodiment: Please refer to Figure 1 The output voltage regulation module includes transistors Q4 and Q5. The collector of transistor Q4 is connected to the current supply module, and the collector of transistor Q5 is connected to the negative input voltage -VIN. The emitter of transistor Q4 is connected to the negative output voltage -V0 through resistor R23. The base of transistor Q4 is connected to the output terminal of amplifier IC5-A through resistor R12. The non-inverting input of amplifier IC5-A is connected to one end of resistor R11. The other end of resistor R11 is connected to one end of resistor R4 and one end of potentiometer R8. The other end of resistor R4 is connected to the positive output voltage +V0, and the other end of potentiometer R8 is connected to... Connect the negative input voltage -VIN. Connect one end of resistor R13 to the inverting input of amplifier IC5-A. Connect the other end of resistor R13 to the reference voltage VREF. Connect one end of resistor R15 to one end of resistor R17 and one end of resistor R18. Connect the other end of resistor R17 to the negative input voltage -VIN. Connect the other end of resistor R18 to the inverting input of amplifier IC5-B. Connect the non-inverting input of amplifier IC5-B to the negative output voltage -V0 through resistor R20. Connect one end of resistor R19 to the output of amplifier IC5-B. Connect the other end of resistor R19 to the base of transistor Q5.

[0031] Let the currents flowing through resistor R5, transistor Q4, and transistor Q5 be I, respectively. R5 I Q4 I Q5 The base current amplification factors of transistors Q3, Q4, and Q5 are β, β1, and β2, respectively, and the output current is I. O。

[0032] Voltage at common point A V A VIN-R5*I R5 Common point E potential V E VIN-R5*I R5 -0.7

[0033] The current I in resistor R6 R6 For β(I) R5 -I Q4 -I Q5 )

[0034] Potential V at common point D D For V E -R6*I R6

[0035] Output voltage V O For V D -0.7-I O* (R1 / / R2 / / Rn)=V E -R6*I R6 -0.7-I O* (R1 / / R2 / / Rn)=V E -R6*β(I R5 -I Q4 -I Q5 -0.7-I O* (R1 / / R2 / / Rn), that is, by adjusting I Q4 with I Q5 The output voltage can be regulated by the current.

[0036] Output voltage V O The voltage is divided by resistor R4 and potentiometer R8, and the potential V at the common point B is... B The potential V at the common point B is VIN*R8 / (R4+R8). B Compared to the reference voltage Vref, the voltage difference is amplified by operational amplifier IC5-A to output current I. IC5A For (Vref-V) B If R13 is constant, then the collector current of transistor Q4 is I. IC5A *β1;

[0037] Then I Q4＝ I IC5A *β1=(Vref-V B ) / R13*β1=(Vref-(VIN*R8 / (R4+R8))) / R13*β1;

[0038] The output voltage can be adjusted by adjusting the resistance value of resistor R8, thereby adjusting the current value of transistor IQ4.

[0039] Voltage V at common point C C For Vref*R 17 / (R17+R18), -V O Point potential V O- With V C In comparison, the voltage difference is amplified by operational amplifier IC5-B to output current I. IC5 For (V) O- -V C If R18, then the collector current of transistor Q5 is I. IC5B *β2;

[0040] Then I Q5＝ I IC5B *β2=(V O- -V C ) / R18*β2=V O- -(Vref*R 17 / (R17+R18))) / R18*β2;

[0041] The current value of transistor IQ4 can be adjusted by adjusting the resistance value of resistor R23, thereby adjusting the output voltage. In other words, adjusting R23 can set the output overcurrent protection threshold.

[0042] By increasing the drive current of transistors Q1 (Q2, Q3...Qn) through transistor Q3, the output current can be increased. Alternatively, by adding transistor Qn and balancing resistor Rn to the branch, the power consumption of a single branch can be reduced, and the output current can be increased.

[0043] In this embodiment: Please refer to Figure 1 The low-noise, high-power adjustable buck circuit further includes:

[0044] The reverse protection module is used to ensure that the control circuit is open when the power supply is connected in the correct direction and closed when the power supply is connected in the reverse direction.

[0045] The reverse protection module includes resistor R16, MOSFET M1, resistor R22, diode D1, and capacitor C6. One end of resistor R16 is connected to the positive input voltage +VIN, and the other end of resistor R16 is connected to the gate of MOSFET M1, one end of resistor R22, the negative terminal of diode D1, and one end of capacitor C6. The drain of MOSFET M1 is connected to the negative input voltage -VIN, and the source of MOSFET M1 is connected to the other end of resistor R22, the positive terminal of diode D1, and the other end of capacitor C6.

[0046] When the input voltage is positive, the gate of MOSFET M1 receives a high level, causing MOSFET M1 to conduct. The negative terminal of the input voltage -VIN passes through MOSFET M1 and resistor R23, resulting in a voltage at the negative terminal of the output voltage -V0, thus forming a circuit.

[0047] When the input voltage is reversed, the gate of MOSFET M1 is at a low level, MOSFET M1 does not conduct, and no loop is formed at the output terminal, thus avoiding the circuit being burned out by reverse connection.

[0048] In this embodiment: Please refer to Figure 1 The low-noise, high-power adjustable buck circuit further includes:

[0049] The series voltage regulator module is used to obtain the operating voltage of the output voltage regulation module;

[0050] The series voltage regulator module includes resistors R3 and R7, transistor Q6, three-terminal regulator IC4, resistors R9 and R10, and capacitor C2. One end of resistor R3 is connected to the positive terminal of the input voltage +VIN, and the other end of resistor R3 is connected to one end of resistor R7 and the collector of transistor Q6. The emitter of transistor Q6 is connected to the voltage regulation module (the output operating voltage VCC is connected to the voltage regulation module). One end of resistor R10 is connected to the base of transistor Q6 and the negative terminal of three-terminal regulator IC4. The other end of resistor R7 is connected to the positive terminal of three-terminal regulator IC4 and the negative terminal of the input voltage -VIN. One end of resistor R9 and one end of capacitor C2 are connected to the other end of resistor R10, the other end of capacitor C2, the reference voltage VREF (2.5V), and the reference terminal of three-terminal regulator IC4.

[0051] The reference voltage VREF at the reference terminal of the three-terminal regulator IC4 is 2.5V, which turns on the three-terminal regulator IC4 and provides a stable voltage to the base of the transistor Q6. The emitter output voltage VCC of the transistor Q6 serves as the operating voltage of the amplifiers IC5-A and IC5-B.

[0052] The working principle of this utility model is as follows: the current supply module is used to provide conduction current to the multi-branch output module; the multi-branch output module is used to output voltage and current through multiple branches, reduce the power consumption of a single branch, and increase the output current; the output voltage adjustment module is used to change the magnitude of the conduction current provided by the current supply module by changing the circuit impedance, thereby adjusting the current magnitude of a single branch in the multi-branch output module, and ultimately changing the magnitude of the output voltage.

[0053] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects.

[0054] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A low-noise, high-power adjustable step-down circuit, characterized in that, This low-noise, high-power adjustable buck circuit includes: A current supply module is used to provide conduction current to the multi-branch output module; Multi-branch output module is used to output voltage and current through multiple branches, thereby reducing the power consumption of a single branch and increasing the output current; The output voltage regulation module is used to change the magnitude of the conduction current provided by the current supply module by changing the circuit impedance, thereby adjusting the current magnitude of a single branch in the multi-branch output module, and ultimately changing the output voltage magnitude. The current supply module connects to multiple branch output modules and the output voltage regulation module.

2. The low-noise, high-power adjustable step-down circuit according to claim 1, characterized in that, The current supply module includes resistor R5, transistor Q3, and resistor R6. One end of resistor R5 is connected to the positive input voltage +VIN and the collector of transistor Q3. The other end of resistor R5 is connected to the base of transistor Q3 and the output voltage regulation module. The emitter of transistor Q3 is connected to one end of resistor R6, and the other end of resistor R6 is connected to the multi-branch output module.

3. The low-noise, high-power adjustable step-down circuit according to claim 1, characterized in that, The multi-branch output module includes multiple branches connected in parallel. Each branch includes a transistor Q1 and a resistor R1. The collector of transistor Q1 is connected to the positive input voltage +VIN, the base of transistor Q1 is connected to the current supply module, and the emitter of transistor Q1 is connected to the positive output voltage +V0.

4. The low-noise, high-power adjustable step-down circuit according to claim 1, characterized in that, The output voltage regulation module includes transistors Q4 and Q5. The collector of transistor Q4 is connected to the current supply module, and the collector of transistor Q5 is also connected. The emitter of transistor Q4 is connected to the negative input voltage -VIN. The emitter of transistor Q5 is connected to the negative output voltage -V0 through resistor R23. The base of transistor Q4 is connected to the output terminal of amplifier IC5-A through resistor R12. The non-inverting input of amplifier IC5-A is connected to one end of resistor R11. The other end of resistor R11 is connected to one end of resistor R4 and one end of potentiometer R8. The other end of resistor R4 is connected to the positive output voltage +V0, and the other end of potentiometer R8 is connected to... The input voltage negative terminal is -VIN. The inverting terminal of amplifier IC5-A is connected to one end of resistor R13. The other end of resistor R13 is connected to the reference voltage VREF. One end of resistor R15 is connected to one end of resistor R17. One end of resistor R18 is connected to the input voltage negative terminal -VIN. The other end of resistor R18 is connected to the inverting terminal of amplifier IC5-B. The non-inverting terminal of amplifier IC5-B is connected to the output voltage negative terminal -V0 through resistor R20. The output terminal of amplifier IC5-B is connected to one end of resistor R19. The other end of resistor R19 is connected to the base of transistor Q5.

5. The low-noise, high-power adjustable step-down circuit according to any one of claims 1 to 4, characterized in that, The low-noise, high-power adjustable step-down circuit also includes: The reverse protection module is used to ensure that the control circuit is open when the power supply is connected in the correct direction and closed when the power supply is connected in the reverse direction. The reverse protection module includes resistor R16, MOSFET M1, resistor R22, diode D1, and capacitor C6. One end of resistor R16 is connected to the positive input voltage +VIN, and the other end of resistor R16 is connected to the gate of MOSFET M1, one end of resistor R22, the negative terminal of diode D1, and one end of capacitor C6. The drain of MOSFET M1 is connected to the negative input voltage -VIN, and the source of MOSFET M1 is connected to the other end of resistor R22, the positive terminal of diode D1, and the other end of capacitor C6.

6. The low-noise, high-power adjustable step-down circuit according to any one of claims 1 to 4, characterized in that, The low-noise, high-power adjustable step-down circuit also includes: The series voltage regulator module is used to obtain the operating voltage of the output voltage regulation module; The series regulation voltage regulator module includes resistor R3, resistor R7, transistor Q6, three-terminal regulator IC4, resistor R9, resistor R10, and capacitor C2. One end of resistor R3 is connected to the positive terminal of the input voltage +VIN, and the other end of resistor R3 is connected to one end of resistor R7, the collector of transistor Q6, the emitter of transistor Q6, the voltage regulation module, one end of resistor R10, the base of transistor Q6, the negative terminal of three-terminal regulator IC4, the other end of resistor R7, the positive terminal of three-terminal regulator IC4, the negative terminal of the input voltage -VIN, one end of resistor R9, one end of capacitor C2, the other end of resistor R9, the other end of resistor R10, the other end of capacitor C2, the reference voltage VREF, and the reference terminal of three-terminal regulator IC4.

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