A low-power lossless DC-DC regulated power supply circuit

Abstract

This utility model discloses a low-power lossless DC-DC regulated power supply circuit, belonging to the field of DC-DC regulated power supply technology. The circuit includes an input filter circuit, a switching converter circuit, a feedback regulation circuit, an output voltage regulator circuit, and a load protection circuit. The feedback regulation circuit improves voltage regulation accuracy through an error amplifier and an adjustable potentiometer, while the switching converter circuit optimizes energy conversion efficiency and reduces losses. This application can adjust the output voltage stability in real time, enhance dynamic response capability, ensure voltage stability during load changes, and significantly improve conversion efficiency, reduce power consumption, and improve thermal management performance, making it suitable for high-precision, low-power scenarios.

Description

Technical Field

[0001] This utility model belongs to the field of DC regulated power supply technology, specifically, it relates to a low-power lossless DC regulated power supply circuit. Background Technology

[0002] With the development of DC regulated power supply technology, various low-power and high-stability power supply circuits have been widely used in industrial control, portable devices, and new energy fields. However, some existing DC regulated power supply circuits still suffer from problems such as low conversion efficiency, high power consumption, and insufficient voltage regulation accuracy, making it difficult to meet the growing demand for high-efficiency and intelligent power supply systems.

[0003] For example, a DC regulated power supply circuit with patent number CN112631357B achieves multi-stage regulated output by setting a first switching module and a second switching module. Although it has low static power consumption and high current carrying capacity, its linear step-down method results in significant energy loss under high voltage differential conditions, limiting the overall conversion efficiency and making it unsuitable for thermal management and energy-saving requirements during long-term operation. Furthermore, a DC regulated power supply output circuit with patent number CN106502296B amplifies, samples, and regulates the voltage through a voltage regulation control module and introduces a feedback mechanism to improve output stability. However, its voltage regulation relies on analog component parameter matching, resulting in limited regulation accuracy and a slow response speed during load changes, affecting the dynamic stability of the output voltage and making it difficult to meet the stringent requirements of modern electronic systems for power supply accuracy and response speed.

[0004] In summary, existing DC regulated power supply circuits still have certain limitations in terms of low power consumption and lossless conversion, especially in terms of conversion efficiency, dynamic response capability, and voltage regulation accuracy, which cannot fully meet the requirements of high-performance applications. Therefore, there is an urgent need to propose a novel low-power lossless conversion DC regulated power supply circuit to overcome the above problems and provide a more efficient and stable power supply solution. Utility Model Content

[0005] The purpose of this invention is to provide a low-power lossless DC regulated power supply circuit, which mainly solves the shortcomings of existing DC regulated power supply circuits in terms of conversion efficiency, dynamic response capability and voltage regulation accuracy.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A low-power lossless DC-DC regulated power supply circuit includes an input filter circuit, a switching circuit, a feedback regulation circuit, an output voltage regulator circuit, and a load protection circuit connected in sequence. The feedback regulation circuit is connected to the load protection circuit, and the output voltage regulator circuit is also connected to the load protection circuit. The feedback regulation circuit includes an error amplifier U1 connected to the output voltage regulator circuit, a resistor R3 connected to the output terminal of the error amplifier U1, an adjustable potentiometer VR1 and a resistor R4 connected in series with the other end of the resistor R3, a transistor Q1 whose base is connected to the other end of the resistor R4, and resistors R1 and R2 connected to the collector of the transistor Q1. The other end of the resistor R1 is connected to the load protection circuit, the other end of the resistor R2 is grounded, the adjustable terminal of the adjustable potentiometer VR1 is connected to the output voltage regulator circuit, and the emitter of the transistor Q1 is connected to the output terminal of the error amplifier U1 and then connected to a reference voltage VREF. The inverting input terminal of the error amplifier U1 is connected to the output voltage regulator circuit.

[0008] Furthermore, in this utility model, the input filtering circuit includes an inductor L1, a capacitor C1, an inductor L2 connected in series, a capacitor C2 connected to one end of the inductor L1 and grounded, and a capacitor C3 connected to the common terminal of the inductor L1 and the capacitor C2; wherein, one end of the capacitor C3 connected to the inductor L2 is connected to the switching circuit, and the other end of the inductor L2 is grounded.

[0009] Furthermore, in this utility model, the switching conversion circuit includes a driver chip U2 whose non-inverting input terminal is connected to one end of the capacitor C3 and the inductor L2, a resistor R5 connected to the inverting input terminal of the driver chip U2, and a capacitor C4 connected between the inverting input terminal of the driver chip U2 and ground; wherein, the output terminal of the driver chip U2 is connected to the feedback adjustment circuit.

[0010] Furthermore, in this invention, the feedback regulation circuit further includes a current-limiting transistor Q2 whose collector is connected to one end of resistor R5, a control transistor Q3 whose collector and base are respectively connected to the base and emitter of the current-limiting transistor Q2, voltage-dividing resistors R6 and R7 connected to the base of the current-limiting transistor Q2, a control switch Q4 whose collector is connected to the other end of resistor R6 and whose emitter is grounded, and sampling resistors R8 and R9 connected in parallel, one end of which is connected to the emitter of the control transistor Q3 and the other end of which is connected to the output terminal of the driver chip U2; wherein, the other end of the voltage-dividing resistor R7 is grounded.

[0011] Furthermore, in this utility model, the output voltage regulator circuit includes a resistor R10 connected to the base of the control switch Q4, a resistor R11 connected to the other end of the resistor R10, and a resistor R12 with one end connected to the other end of the resistor R11 and the other end serving as the output; wherein, the common terminal of the resistors R11 and R12 is connected to the load protection circuit and the inverting input terminal of the error amplifier U1.

[0012] Furthermore, in this utility model, the load protection circuit includes a resistor R13 with one end connected to the common terminal of resistors R11 and R12, a resistor R14 with one end connected to the common terminal of resistors R10 and R11, a resistor R15 with one end connected to the other ends of resistors R13 and R14, a resistor R16 connected to the output terminal of resistor R12, a diode D1 with its positive terminal connected to the other end of resistor R15 and its negative terminal connected to the other end of resistor R16, a diode D2 with its negative terminal connected to the other end of resistor R15 and its positive terminal connected to the other end of resistor R16, a capacitor C5 connected in parallel across diode D2, an operational amplifier U3 with its positive input terminal connected to the negative terminal of diode D2 and its negative input terminal connected to the positive terminal of diode D2, and a Zener diode D3 with its negative terminal connected to the output terminal of operational amplifier U3 and its positive terminal grounded; wherein, the output terminal of operational amplifier U3 is also connected to the positive input terminal of error amplifier U1.

[0013] Furthermore, in this invention, the inductor L1, capacitor C1, inductor L2, capacitor C2, and capacitor C3 in the input filter circuit constitute an LC filter structure, used to filter out high-frequency noise and ripple in the input power supply.

[0014] Furthermore, in this utility model, the diodes D1, D2, C5, operational amplifier U3, and Zener diode D3 in the load protection circuit constitute an overcurrent or overvoltage protection module, which is used to trigger the protection mechanism under abnormal conditions.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) This utility model reduces energy loss under high voltage difference conditions by optimizing the switching conversion circuit (such as the driver chip U2 combined with PWM control), and solves the problem of limited conversion efficiency caused by the linear step-down method in the prior art. It is suitable for low power consumption scenarios that require long-term operation.

[0017] (2) The feedback regulation circuit of this utility model adopts the error amplifier U1 and the adjustable potentiometer VR1 working together to dynamically adjust the working state of transistor Q1, thereby achieving precise regulation of the output voltage. This avoids the problem of insufficient accuracy caused by the parameter matching dependence of traditional analog components and meets the requirements of high-precision voltage regulation.

[0018] (3) The feedback regulation circuit and the output voltage regulator circuit of this utility model form a closed-loop control, which can monitor and adjust the output voltage in real time and quickly restore stability when the load changes suddenly (such as detecting the current change through sampling resistors R8 and R9 and triggering current limiting protection), which solves the problem of slow response speed when the load changes suddenly in the prior art.

[0019] (4) The load protection circuit of this utility model consists of diodes D1 / D2, operational amplifier U3 and Zener diode D3 to form an overcurrent / overvoltage protection module. Under abnormal conditions, protection can be triggered (such as cutting off the output or reducing the power), which improves the reliability and safety of the circuit. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall circuit structure of this utility model. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0022] Example

[0023] This invention provides a low-power, lossless DC-DC regulated power supply circuit, the overall architecture of which is as follows: Figure 1 As shown, the system includes an input filter circuit, a switching converter circuit, a feedback regulation circuit, an output voltage regulator circuit, and a load protection circuit. These modules work together through specific connections to achieve efficient and stable DC-DC voltage conversion. The specific embodiments of this invention will be described in detail below with reference to the accompanying drawings.

[0024] First, the input filter circuit, as the front-end of the entire circuit, is mainly used to filter out high-frequency noise and ripple in the input power supply, ensuring that subsequent circuits can obtain a relatively clean DC input signal. Specifically, the input filter circuit consists of inductor L1, capacitor C1, inductor L2, capacitor C2, and capacitor C3. One end of inductor L1 is connected to the external DC power supply, and the other end is connected to one end of capacitor C1; the other end of capacitor C1 is connected to one end of inductor L2 and also to one end of capacitor C3; the other end of capacitor C3 is connected to the switching circuit, while the other end of inductor L2 is grounded. Furthermore, one end of capacitor C2 is connected to the common terminal of inductor L1 and capacitor C1, and the other end is grounded. This design effectively suppresses high-frequency interference at the input end using the characteristics of an LC filter, providing a stable input environment for subsequent circuits. In practical applications, when the input voltage fluctuates or high-frequency noise is present, the input filter circuit can quickly respond and filter it out, thereby ensuring the normal operation of subsequent circuits.

[0025] Next, the switching converter circuit is responsible for efficiently converting the filtered DC input voltage into energy. The core component of this circuit is the driver chip U2, whose non-inverting input is connected to capacitor C3 in the input filter circuit, and its inverting input is grounded through resistor R5. A capacitor C4 is also connected between the inverting input and ground. The output of driver chip U2 is connected to a feedback regulation circuit, which adjusts the switching frequency and duty cycle based on the feedback signal, thereby achieving precise control of the output voltage. In actual operation, driver chip U2 is model UC3842. This chip generates a high-frequency switching signal through its internal PWM controller, driving the power switching transistor to periodically turn on and off, converting the input DC voltage into pulsed energy output. This process not only improves energy conversion efficiency but also reduces energy loss under high voltage differential conditions, thus significantly improving the overall performance of the circuit.

[0026] The feedback regulation circuit is one of the core components of this invention. Its main function is to monitor and regulate the output voltage in real time to ensure its stability and accuracy. The feedback regulation circuit includes an error amplifier U1, an adjustable potentiometer VR1, a transistor Q1, and related resistors. The non-inverting input of the error amplifier U1 is connected to the reference voltage VREF, and the inverting input is connected to the output voltage regulator circuit, used to compare the difference between the reference voltage and the actual output voltage. The output of the error amplifier U1 is connected to one end of the adjustable potentiometer VR1 through a resistor R3. The other end of the adjustable potentiometer VR1 is connected in series with a resistor R4 and the base of the transistor Q1. The collector of the transistor Q1 is connected to resistors R1 and R2, with the other end of resistor R1 connected to the load protection circuit and the other end of resistor R2 grounded. Furthermore, the adjustable terminal of the adjustable potentiometer VR1 is directly connected to the output voltage regulator circuit, while the emitter of the transistor Q1 is connected to the output of the error amplifier U1 and then to the reference voltage VREF. Through the above connection method, the feedback regulation circuit can dynamically adjust the operating state of transistor Q1 according to changes in the output voltage, thereby changing the circuit gain and feedback quantity to keep the output voltage within the set range. In practical applications, when the load changes or the input voltage fluctuates, the feedback regulation circuit can respond quickly and restore the stability of the output voltage through a closed-loop control mechanism, thus meeting the requirements of high-precision voltage regulation.

[0027] In this embodiment, the feedback regulation circuit also includes components such as a current-limiting transistor Q2, a control transistor Q3, voltage divider resistors R6 and R7, a control switch Q4, and sampling resistors R8 and R9. The collector of the current-limiting transistor Q2 is connected to one end of resistor R5, its base is grounded through voltage divider resistors R6 and R7, and its emitter is connected to the base of the control transistor Q3. The collector of the control transistor Q3 is connected to the other end of voltage divider resistor R6, and its emitter is grounded. The collector of the control switch Q4 is connected to the other end of voltage divider resistor R6, its emitter is grounded, and its base is connected to resistor R10. Sampling resistors R8 and R9 are connected in parallel, with one end connected to the emitter of the control transistor Q3 and the other end connected to the output terminal of the driver chip U2. These components together constitute a precise current detection and current-limiting protection mechanism, which can automatically reduce the output power of the driver chip U2 when the output current exceeds a set threshold, thereby preventing overcurrent damage to the circuit.

[0028] In this embodiment, the main function of the output voltage regulator circuit is to convert the pulse voltage processed by the switching converter circuit and the feedback adjustment circuit into a stable DC output voltage. This circuit includes resistors R10, R11, and R12. One end of resistor R10 is connected to the base of the control switch Q4, and the other end is connected to one end of resistor R11. The other end of resistor R11 is connected to one end of resistor R12, and the other end of resistor R12 serves as the output terminal of the DC regulated power supply circuit. The common terminal of resistors R11 and R12 is connected to the load protection circuit and the inverting input of the error amplifier U1, providing a sampling signal to the load protection circuit. By appropriately selecting the values ​​of resistors R10, R11, and R12, the output voltage can be precisely set. During actual operation, the output voltage regulator circuit detects the voltage drop across the sampling resistors and feeds the detection result back to the feedback adjustment circuit, thus forming a closed-loop control system to ensure that the output voltage is always maintained near the target value.

[0029] Finally, the load protection circuit detects the current and voltage status at the output terminal and takes protective measures to prevent circuit damage in abnormal situations. The load protection circuit includes resistors R13, R14, R15, and R16, diodes D1 and D2, capacitor C5, operational amplifier U3, and Zener diode D3. One end of resistor R13 is connected to the common terminal of resistors R11 and R12, and the other end is connected to one end of resistor R15. One end of resistor R14 is connected to the common terminal of resistors R10 and R11, and the other end is connected to one end of resistor R15. The other end of resistor R15 is connected to the anode of diode D1 and the cathode of diode D2. The cathode of diode D1 is connected to one end of resistor R16, and the anode of diode D2 is connected to the other end of resistor R16, which is grounded. Capacitor C5 is connected in parallel across diode D2 to absorb transient voltage spikes. The non-inverting input of operational amplifier U3 is connected to the cathode of diode D2, the non-inverting input is connected to the anode of diode D2, and the output is connected to the cathode of Zener diode D3, with the anode of Zener diode D3 grounded. Furthermore, the output of operational amplifier U3 is also connected to the non-inverting input of error amplifier U1 to provide a protection signal to the feedback adjustment circuit. In practical applications, when overcurrent or overvoltage occurs at the output, the load protection circuit can quickly detect the abnormal state and trigger a protection mechanism through the operation of operational amplifier U3 and Zener diode D3, such as cutting off the output or reducing the output power, thereby effectively protecting the circuit from damage.

[0030] In summary, this invention achieves efficient, stable, and reliable DC-DC voltage conversion through the coordinated operation of the input filtering circuit, switching conversion circuit, feedback regulation circuit, output voltage regulation circuit, and load protection circuit. In practical applications, this circuit is widely applicable to scenarios requiring high-precision voltage regulation and low-power operation, such as portable electronic devices, communication base station power systems, and industrial automation equipment. By optimizing the design and parameter configuration of each module, this invention not only significantly improves energy conversion efficiency and dynamic response capability but also possesses excellent voltage regulation accuracy and load adaptability, fully meeting the high-performance requirements of modern electronic devices for power systems.

[0031] The above embodiments are merely one of the preferred embodiments of this utility model and should not be used to limit the scope of protection of this utility model. Any modifications or refinements made to the main design concept and spirit of this utility model that are not of substantial significance, but solve the same technical problem as this utility model, should be included within the scope of protection of this utility model.

Claims

1. A low-power-loss conversion DC regulated power supply circuit, characterized by comprising: a DC power supply source; a DC-DC converter; a DC-AC converter; a rectifier; a smoothing capacitor; a control circuit; and a load. The system includes an input filter circuit, a switching circuit, a feedback regulation circuit, an output voltage regulator circuit, and a load protection circuit connected in sequence. The feedback regulation circuit is connected to the load protection circuit, and the output voltage regulator circuit is also connected to the load protection circuit. The feedback regulation circuit includes an error amplifier U1 connected to the output voltage regulator circuit, a resistor R3 connected to the output terminal of the error amplifier U1, an adjustable potentiometer VR1 and a resistor R4 connected in series with the other end of the resistor R3, a transistor Q1 whose base is connected to the other end of the resistor R4, and resistors R1 and R2 connected to the collector of the transistor Q1. The other end of the resistor R1 is connected to the load protection circuit, the other end of the resistor R2 is grounded, the adjustable terminal of the adjustable potentiometer VR1 is connected to the output voltage regulator circuit, and the emitter of the transistor Q1 is connected to the output terminal of the error amplifier U1 and then connected to a reference voltage VREF. The inverting input terminal of the error amplifier U1 is connected to the output voltage regulator circuit.

2. The low-power-loss DC-DC converter circuit according to claim 1, wherein The input filtering circuit includes an inductor L1, a capacitor C1, an inductor L2 connected in series, a capacitor C2 connected to one end of the inductor L1 and grounded, and a capacitor C3 connected to the common terminal of the inductor L1 and the capacitor C2; wherein, one end of the capacitor C3 connected to the inductor L2 is connected to the switching circuit, and the other end of the inductor L2 is grounded.

3. The low power loss DC to DC conversion voltage regulator circuit of claim 2, wherein, The switching conversion circuit includes a driver chip U2 whose non-inverting input terminal is connected to one end of the capacitor C3 and the inductor L2, a resistor R5 connected to the inverting input terminal of the driver chip U2, and a capacitor C4 connected between the inverting input terminal of the driver chip U2 and ground; wherein, the output terminal of the driver chip U2 is connected to the feedback adjustment circuit.

4. The low power loss DC to DC conversion voltage regulator circuit of claim 3, wherein, The feedback regulation circuit also includes a current-limiting transistor Q2 whose collector is connected to one end of resistor R5, a control transistor Q3 whose collector and base are connected to the base and emitter of the current-limiting transistor Q2, respectively, voltage-dividing resistors R6 and R7 connected to the base of the current-limiting transistor Q2, a control switch Q4 whose collector is connected to the other end of resistor R6 and whose emitter is grounded, and sampling resistors R8 and R9 connected in parallel, with one end connected to the emitter of the control transistor Q3 and the other end connected to the output terminal of the driver chip U2; wherein, the other end of the voltage-dividing resistor R7 is grounded.

5. The low power loss DC to DC converter circuit of claim 4, wherein, The output voltage regulator circuit includes a resistor R10 connected to the base of the control switch Q4, a resistor R11 connected to the other end of the resistor R10, and a resistor R12 with one end connected to the other end of the resistor R11 and the other end serving as the output; wherein, the common terminal of the resistors R11 and R12 is connected to the load protection circuit and the inverting input terminal of the error amplifier U1.

6. The low power loss DC to DC conversion voltage regulator circuit of claim 5, wherein, The load protection circuit includes a resistor R13 with one end connected to the common terminal of resistors R11 and R12, a resistor R14 with one end connected to the common terminal of resistors R10 and R11, a resistor R15 with one end connected to the other ends of resistors R13 and R14, a resistor R16 connected to the output terminal of resistor R12, a diode D1 with its positive terminal connected to the other end of resistor R15 and its negative terminal connected to the other end of resistor R16, a diode D2 with its negative terminal connected to the other end of resistor R15 and its positive terminal connected to the other end of resistor R16, a capacitor C5 connected in parallel across diode D2, an operational amplifier U3 with its positive input terminal connected to the negative terminal of diode D2 and its negative input terminal connected to the positive terminal of diode D2, and a Zener diode D3 with its negative terminal connected to the output terminal of operational amplifier U3 and its positive terminal grounded; wherein, the output terminal of operational amplifier U3 is also connected to the positive input terminal of error amplifier U1.

7. The low power loss DC to DC converter circuit of claim 6, wherein, The inductor L1, capacitor C1, inductor L2, capacitor C2, and capacitor C3 in the input filter circuit constitute an LC filter structure, which is used to filter out high-frequency noise and ripple in the input power supply.

8. The low power loss DC to DC conversion voltage regulator circuit of claim 7, wherein, The diodes D1, D2, C5, operational amplifier U3, and Zener diode D3 in the load protection circuit constitute an overcurrent or overvoltage protection module, which is used to trigger the protection mechanism under abnormal conditions.

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