A very low output voltage and output current programmable constant resistance power supply circuit

Abstract

The application provides a very low output voltage and output current programmable constant resistance power supply circuit, which comprises a differential amplifier A and a differential amplifier B, the non-inverting input terminal of the differential amplifier B is connected with an external input voltage, the inverting input terminal of the differential amplifier B is connected with a programmable control reference voltage Vref, the output terminal of the differential amplifier B is electrically connected with the inverting input terminal of the differential amplifier A, and the inverting input terminal of the differential amplifier A is connected with the external input voltage; the output level is fed back to the differential amplifier A as an input through the differential amplifier B after the programmable control reference voltage Vref, and the output of the differential amplifier A controls the conduction degree of a MOS transistor Q20, so that the very low output voltage and the driving current of a large load can be realized by adjusting the parameters of the MOS transistor Q20 and the current of the reference voltage Vref, and the whole circuit is simple and ingenious in design and low in cost.

Description

Technical Field

[0001] This invention relates to the field of power supply circuit technology, specifically to a programmable constant resistance power supply circuit with ultra-low output voltage and output current. Background Technology

[0002] In the era of Industry 4.0, with the rise of global automation and unmanned living and production methods, the demand for high-end intelligent equipment in production and daily life urgently requires a smart power supply that can be automatically programmed by AI or remotely controlled by humans to provide sustainable power for industrial equipment and ensure its stable and efficient operation. Traditional power supplies with fixed output voltage and current cannot meet the needs of these new intelligent devices, making the design of an intelligent programmable power supply particularly urgent! An intelligent programmable power supply is a power supply whose output can be controlled by computer programming. It can automatically adjust the output voltage and current according to the user's needs, thereby meeting the user's personalized requirements. Programmable power supplies have advantages such as energy saving, good stability, and high reliability, making them a highly efficient and intelligent power supply.

[0003] However, existing programmable power supplies have drawbacks such as insufficient constant resistance accuracy in ultra-low voltage / current scenarios, poor programmability, and lack of safety and stability. Summary of the Invention

[0004] In view of the deficiencies in the existing technology, the purpose of this invention is to provide a programmable constant resistance power supply circuit with a simple circuit structure, low cost, and capable of achieving low voltage output and large load drive current, and with ultra-low output voltage and output current.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a programmable constant resistance power supply circuit with ultra-low output voltage and output current, comprising a differential amplifier A and a differential amplifier B. The non-inverting input terminal of the differential amplifier B is connected to an external input voltage, and the inverting input terminal of the differential amplifier B is connected to a programmable reference voltage Vref. The output terminal of the differential amplifier B is electrically connected to the inverting input terminal of the differential amplifier A. The non-inverting input terminal of the differential amplifier A is connected to the external input voltage. The output terminal of the differential amplifier A is electrically connected to the drain of a MOSFET Q20. The gate of the MOSFET Q20 is connected to the external input voltage, and the source of the MOSFET Q20 is grounded.

[0006] Furthermore, a capacitor C26 and a resistor R33 connected in parallel are installed between the inverting input terminal and the output terminal of the differential amplifier B.

[0007] Furthermore, a capacitor C28 and a resistor R34 connected in parallel are installed between the non-inverting input terminal and the inverting input terminal of the differential amplifier A.

[0008] Furthermore, a resistor R6 is connected in series at the output terminal of the differential amplifier A.

[0009] Furthermore, a capacitor C23 and a resistor R62 connected in parallel are installed between the gate and source of the MOS transistor.

[0010] The beneficial effects of this invention are as follows:

[0011] The ultra-low output voltage and output current programmable constant resistance power supply circuit of this invention achieves high-precision constant resistance control under ultra-low voltage and weak current by optimizing circuit topology, improving analog-to-digital conversion accuracy, strengthening safety isolation design and intelligent control algorithm. It supports programmable adjustment of voltage, current and resistance parameters and intelligent communication, while meeting SELV circuit safety standards and low ripple and high efficiency requirements. It fills the gap in the field of ultra-low voltage programmable constant resistance power supplies and is suitable for the core needs of applications in precision testing, industrial control, communication equipment, medical instruments, laboratory equipment, aerospace, drones and robots and other automation fields.

[0012] The ultra-low output voltage and output current programmable constant resistance power supply circuit of the present invention has the following advantages: 1. The circuit design is simple and ingenious, and the cost is low; 2. The output voltage is extremely low and the output voltage is programmable and adjustable; 3. The output current is large and the output current is programmable and adjustable; 4. It can output according to the waveform and frequency of a given IREF. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the differential amplifier B in the programmable constant resistance power supply circuit with ultra-low output voltage and output current in the embodiments of this application.

[0014] Figure 2 This is a schematic diagram of the differential amplifier A in the programmable constant resistance power supply circuit with ultra-low output voltage and output current in the embodiments of this application.

[0015] Figure 3 This is a schematic diagram illustrating the current structure of the differential amplifier A connected to the MOS transistor in the programmable constant resistance power supply circuit with ultra-low output voltage and output current in the embodiments of this application. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0017] Reference Figures 1 to 3As shown, this embodiment provides a programmable constant resistance power supply circuit with ultra-low output voltage and output current, including differential amplifier A and differential amplifier B. The non-inverting input terminal of differential amplifier B is connected to an external input voltage, and the inverting input terminal of differential amplifier B is connected to a programmable reference voltage Vref. The given signal of the reference voltage Vref can be controlled by programming.

[0018] Continue to refer to Figures 1 to 3 As shown, the output terminal of differential amplifier B is electrically connected to the inverting input terminal of differential amplifier A, the non-inverting input terminal of differential amplifier A is connected to the external input voltage, the output terminal of differential amplifier A is electrically connected to the drain of MOSFET Q20, the gate of MOSFET Q20 is connected to the external input voltage, and the source of MOSFET Q20 is grounded.

[0019] The ultra-low output voltage and output current programmable constant resistance power supply circuit in this embodiment uses differential amplifier A and differential amplifier B as the main signal amplification devices. The given signal Vref is remotely programmed or automatically controlled by the device. Vref, after passing through differential amplifier B, feeds its output level back to differential amplifier A as input. The output of differential amplifier A controls the conduction level of the MOSFET. When the Vref level increases, the output of differential amplifier B decreases, the output of differential amplifier A increases, and the MOSFET conduction weakens; when Vref decreases, the output of differential amplifier B increases, the output of differential amplifier A decreases, and the MOSFET conduction strengthens. By adjusting the parameters of R6 and the MOSFET in the circuit, and programming the current of Vref, an extremely low output voltage of 0.3-0.5V can be achieved, with an accuracy reaching the mV level.

[0020] Reference Figure 1 As shown, in order to improve the stability of the circuit, a capacitor C26 and a resistor R33 are connected in parallel between the inverting input and output terminals of the differential amplifier B.

[0021] Reference Figure 2 As shown, in order to improve the high-frequency interference resistance of the entire circuit system while maintaining the necessary signal bandwidth and DC accuracy, a capacitor C28 and a resistor R34 connected in parallel are installed between the non-inverting input terminal and the inverting input terminal of differential amplifier A.

[0022] Reference Figure 3 As shown, in order to adjust the output voltage, in this embodiment, a resistor R6 is connected in series at the output terminal of the differential amplifier A. By adjusting the resistance value of resistor R6, the output voltage of the circuit can be changed.

[0023] Reference Figure 3 As shown, in order to improve the stability and reliability of the circuit, a capacitor C23 and a resistor R62 connected in parallel are installed between the gate and source of the MOSFET.

[0024] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention is also intended to include these modifications and variations.

Claims

1. A programmable constant resistance power supply circuit with ultra-low output voltage and output current, characterized in that, The system includes differential amplifier A and differential amplifier B. The non-inverting input of differential amplifier B is connected to an external input voltage, and the inverting input of differential amplifier B is connected to a programmable reference voltage Vref. The output of differential amplifier B is electrically connected to the inverting input of differential amplifier A. The non-inverting input of differential amplifier A is connected to the external input voltage. The output of differential amplifier A is electrically connected to the drain of MOSFET Q20. The gate of MOSFET Q20 is connected to the external input voltage, and the source of MOSFET Q20 is grounded.

2. The programmable constant resistance power supply circuit with ultra-low output voltage and output current according to claim 1, characterized in that, A capacitor C26 and a resistor R33 are connected in parallel between the inverting input and output terminals of the differential amplifier B.

3. A programmable constant resistance power supply circuit with ultra-low output voltage and output current according to claim 1 or 2, characterized in that, A capacitor C28 and a resistor R34 are connected in parallel between the non-inverting input and the inverting input of the differential amplifier A.

4. The programmable constant resistance power supply circuit with ultra-low output voltage and output current according to claim 1, characterized in that, A resistor R6 is also connected in series at the output terminal of the differential amplifier A.

5. The programmable constant resistance power supply circuit with ultra-low output voltage and output current according to claim 1, characterized in that, A capacitor C23 and a resistor R62 are connected in parallel between the gate and source of the MOS transistor.

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