Non-isolated positive and negative voltage power supply circuit
By designing the buck output circuit and the negative voltage output circuit as the same circuit module and changing the grounding network, non-isolated positive and negative voltage power supply is achieved, solving the problems of complex and low modularity of existing circuit design, and achieving a high modular, low cost and high efficiency circuit design.
Patent Information
- Application Number
- CN202521334900.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2035-06-27
AI Technical Summary
The existing step-down and negative voltage output circuits are complex in design, low in modularity, and the use of transformers leads to complex circuit design, large size, low conversion efficiency, and high cost.
The non-isolated positive and negative voltage power supply circuit is adopted, and the buck output circuit and the negative voltage output circuit are designed as the same circuit module, and the DCDC chip and filtering, feedback adjustment, loop compensation, free-current and protection circuits are used to realize positive and negative voltage power supply, and the circuit cascade is realized by changing the grounding network.
It realizes a high degree of circuit modularity, reduces component types, and reduces procurement costs. It has a simple circuit design, small size, high conversion efficiency and fast response speed.
Smart Images
Figure CN223182025U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of power electronics, in particular to a non-isolated positive and negative voltage power supply circuit. Background Art
[0002] The buck output circuit is a positive voltage circuit with an output voltage lower than the input voltage, and is widely used in various electronic devices (such as computers, mobile phones, tablets, etc.). The negative voltage output circuit is a circuit that can generate a voltage lower than the reference ground potential, such as -5V, -12V, etc., and is often used in scenarios that require dual power supply or specific negative voltage requirements. The core principle of the negative voltage output circuit is to reverse the input positive voltage into a negative voltage output through charge transfer or energy conversion.
[0003] Generally, the implementation methods of buck and negative voltage output include: combining a buck circuit with a buck-boost circuit, and multi-winding output isolation circuits such as forward and flyback. However, in the method of combining a buck circuit with a buck-boost circuit, due to the different circuit topologies and circuit parameter designs of the two circuits, the overall design is relatively complex, and it does not have the ability of module generalization and replication; the flyback circuit generates positive and negative voltage power supply through two windings on the secondary side of the transformer. Due to the use of the transformer, problems such as complex circuit design, large volume, low conversion efficiency, and high cost occur, and urgent improvement is needed. Summary of the Utility Model
[0004] The purpose of the utility model is to provide a non-isolated positive and negative voltage power supply circuit to at least solve the technical problems of complex existing circuit design and weak modularization degree.
[0005] The utility model provides a non-isolated positive and negative voltage power supply circuit, including: a buck output circuit, a negative voltage output circuit, and a positive and negative voltage power supply device. The input end of the buck output circuit is electrically connected to a +24V power supply, and the output end of the buck output circuit is electrically connected to the input end of the negative voltage output circuit and the first input end of the positive and negative voltage power supply device; the output end of the negative voltage output circuit is electrically connected to the second input end of the positive and negative voltage power supply device; the buck output circuit and the negative voltage output circuit are circuit modules with the same devices.
[0006] Preferably, each circuit module includes: a DCDC chip and an input filter circuit, an output filter circuit, a feedback regulation circuit, a loop compensation circuit, a freewheeling circuit, and a protection circuit that are electrically connected to the DCDC chip.
[0007] Preferably, the input filter circuit in the step-down output circuit is electrically connected to the +24V power supply, the feedback regulation circuit in the step-down output circuit is electrically connected to the +15V voltage, the output filter circuit in the step-down output circuit is electrically connected to the +15V voltage and the input filter circuit in the negative voltage output circuit, the feedback regulation circuit in the negative voltage output circuit is electrically connected to the -15V voltage, and the output filter circuit in the negative voltage output circuit is electrically connected to the -15V voltage.
[0008] Preferably, the input filter circuit includes: three capacitors connected in parallel.
[0009] Preferably, the output filter circuit includes: an inductor and three capacitors connected in parallel.
[0010] Preferably, the feedback regulation circuit includes: two resistors and a capacitor.
[0011] Preferably, the loop compensation circuit includes: two capacitors and a resistor.
[0012] Preferably, both the freewheeling circuit and the protection circuit include: diodes.
[0013] The non-isolated positive and negative power supply circuit provided by the present utility model has exactly the same topological structure and devices for the step-down output circuit and the negative voltage output circuit. By changing the grounding network and cascading the same circuit modules, the functions of positive and negative output voltages are realized, thus having the advantages of high modularity, significantly reducing the types of components, and reducing the procurement cost. At the same time, because a non-isolated circuit is used, the circuit design is simple, the overall volume is small, the conversion efficiency is high, and the response speed to load mutations is faster. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0015] Figure 1 It is a structural block diagram of the non-isolated positive and negative power supply circuit according to the embodiment of the present utility model.
[0016] Figure 2 It is a schematic diagram of the non-isolated positive and negative power supply circuit according to the embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0017] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the following will describe in detail the specific embodiments of the present utility model with reference to the accompanying drawings. It should be understood that many specific details are set forth in the following description to facilitate a thorough understanding of the present utility model. However, the present utility model can be implemented in many other ways different from those described herein. Those skilled in the art can make similar improvements without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.
[0018] As Figure 1 and Figure 2 shown, this embodiment provides a non-isolated positive and negative power supply circuit, including: a buck output circuit 1, a negative voltage output circuit 2, and a positive and negative power supply device 3.
[0019] The input end of the buck output circuit 1 is electrically connected to the +24V power supply, and the output end of the buck output circuit 1 is electrically connected to the input end of the negative voltage output circuit 2 and the first input end of the positive and negative power supply device 3; the output end of the negative voltage output circuit 2 is electrically connected to the second input end of the positive and negative power supply device 3.
[0020] In this embodiment, the buck output circuit 1 and the negative voltage output circuit 2 are circuit modules with the same components. Therefore, the circuit design in this embodiment is simple, the types of components are few, and the circuit modules achieve replicability, having the advantages of strong modularity and low cost. Preferably, each circuit module includes: a DCDC chip and an input filter circuit, an output filter circuit, a feedback regulation circuit, a loop compensation circuit, a freewheeling circuit, and a protection circuit that are electrically connected to the DCDC chip.
[0021] Preferably, the pins of the DCDC chip include: a power input pin VCC, a voltage reference pin VREF, a feedback pin FB, a voltage output pin OUT, a master-slave synchronization pin SYNC, a logic signal pin INH, a loop compensation pin COMP, and two ground pins GND. Using a DCDC chip can improve the conversion efficiency.
[0022] In the buck output circuit 1, denoted as: the first DCDC chip U1, the first input filter circuit 10, the first output filter circuit 11, the first feedback regulation circuit 12, the first loop compensation circuit 13, the first freewheeling circuit 14, and the first protection circuit 15. In the negative voltage output circuit 2, denoted as: the second DCDC chip U2, the second input filter circuit 20, the second output filter circuit 21, the second feedback regulation circuit 22, the second loop compensation circuit 23, the second freewheeling circuit 24, and the second protection circuit 25.
[0023] As an example, the types of the first DCDC chip U1 and the second DCDC chip U2 are both DCDC step-down power chips, and the chip model is L5973D013TR.
[0024] The input filter circuit (i.e., the first input filter circuit 10) in the step-down output circuit 1 is electrically connected to the +24V power supply, the feedback regulation circuit (i.e., the first feedback regulation circuit 12) in the step-down output circuit 1 is electrically connected to the +15V voltage, the output filter circuit (i.e., the first output filter circuit 11) in the step-down output circuit 1 is electrically connected to the +15V voltage and the input filter circuit (i.e., the second input filter circuit 20) in the negative voltage output circuit 2, the feedback regulation circuit (i.e., the second feedback regulation circuit 22) in the negative voltage output circuit 2 is electrically connected to the -15V voltage, and the output filter circuit (i.e., the second output filter circuit 21) in the negative voltage output circuit 2 is electrically connected to the -15V voltage.
[0025] Here, the step-down output circuit 1 is for converting +24V to +15V, and the negative voltage output circuit 2 is for converting +15V to -15V. The +15V voltage output by the step-down output circuit 1 and the -15V voltage output by the negative voltage output circuit 2 both supply power to the positive and negative voltage supply device 3. Specifically, the +15V voltage output by the step-down output circuit 1 serves as the input voltage of the negative voltage output circuit 2 and also as the power supply voltage of the positive and negative voltage supply device 3.
[0026] Preferably, both the freewheeling circuit and the protection circuit include: diodes. As an example, the first freewheeling circuit 14 includes: diode D1, the first protection circuit 15 includes: diode D2, the second freewheeling circuit 24 includes: diode D3, and the second protection circuit 25 includes: diode D4.
[0027] The first input filter circuit 10 includes: three capacitors connected in parallel, denoted as: capacitor C1, capacitor C2, and capacitor C3. One end of the parallel combination of capacitor C1, capacitor C2, and capacitor C3 is electrically connected to the negative electrode of diode D1 and the power input pin of the first DCDC chip U1; the other end of the parallel combination of capacitor C1, capacitor C2, and capacitor C3 is electrically connected to a ground pin of the first DCDC chip U1.
[0028] The first feedback regulation circuit 12 includes: two resistors and a capacitor, denoted as: resistor R1, resistor R2, and capacitor C9. The other end of the parallel combination of capacitor C1, capacitor C2, and capacitor C3 is electrically connected to one end of resistor R1 and one end of capacitor C9 and then grounded. The other end of resistor R1 is electrically connected to one end of resistor R2 and the feedback pin of the first DCDC chip U1, and the other ends of resistor R2 and capacitor C9 are both electrically connected to the +15V voltage.
[0029] The first output filter circuit 11 includes: an inductor and three parallel capacitors, denoted as: inductor L1, capacitor C4, capacitor C5, and capacitor C6. One end of the parallel combination of capacitor C4, capacitor C5, and capacitor C6 is electrically connected to one end of inductor L1; the other end of the parallel combination of capacitor C4, capacitor C5, and capacitor C6 is electrically connected to the positive electrode of diode D2 and then grounded; the other end of inductor L1 is electrically connected to the positive electrode of the diode D1, the voltage output pin of the first DC-DC chip U1, and the negative electrode of diode D2.
[0030] The first loop compensation circuit 13 includes: two capacitors and a resistor, denoted as: capacitor C7, capacitor C8, and resistor R3. One end of the series combination of capacitor C7 and resistor R3 is connected in parallel with capacitor C8, and the formed one end is electrically connected to the loop compensation pin of the first DC-DC chip U1, and the formed other end is electrically connected to the positive electrode of diode D2 and another ground pin of the first DC-DC chip U1.
[0031] The second input filter circuit 20 includes: three parallel capacitors, denoted as: capacitor C10, capacitor C11, and capacitor C12. One end of the parallel combination of capacitor C10, capacitor C11, and capacitor C12 is electrically connected to the negative electrode of diode D3 and the power input pin of the second DC-DC chip U2; the other end of the parallel combination of capacitor C10, capacitor C11, and capacitor C12 is electrically connected to a ground pin of the second DC-DC chip U2.
[0032] One end of the parallel combination of capacitor C4, capacitor C5, and capacitor C6 and one end of the parallel combination of capacitor C10, capacitor C11, and capacitor C12 are both electrically connected to the +15V voltage, and this +15V voltage supplies power to the positive and negative voltage supply device 3.
[0033] The second feedback adjustment circuit 22 includes: two resistors and a capacitor, denoted as: resistor R4, resistor R5, and capacitor C18. The other end of the parallel combination of capacitor C10, capacitor C11, and capacitor C12, one end of resistor R4, and one end of capacitor C18 are all electrically connected to the -15V voltage. The other end of resistor R4 is electrically connected to one end of resistor R5 and the feedback pin of the second DC-DC chip U2. The other end of resistor R5 and the other end of capacitor C18 are electrically connected and then grounded.
[0034] The second output filtering circuit 21 includes: an inductor and three parallel capacitors, denoted as: inductor L2, capacitor C13, capacitor C14, and capacitor C15. One end of the parallel combination of capacitor C13, capacitor C14, and capacitor C15 is electrically connected to one end of inductor L2 and then grounded; the other end of the parallel combination of capacitor C13, capacitor C14, and capacitor C15 and the positive electrode of diode D4 are both electrically connected to the -15V voltage, and this -15V voltage supplies power to the positive and negative voltage supply device 3; the other end of inductor L2 is electrically connected to the positive electrode of diode D3, the voltage output pin of the second DCDC chip U2, and the negative electrode of diode D4.
[0035] The second loop compensation circuit 23 includes: two capacitors and a resistor, denoted as: capacitor C16, capacitor C17, and resistor R6. One end of the combination formed by connecting capacitor C16 and resistor R6 in series and then in parallel with capacitor C17 is electrically connected to the loop compensation pin of the second DCDC chip U2, and the other end formed is electrically connected to the positive electrode of diode D4 and another ground pin of the second DCDC chip U2.
[0036] The working process of the buck output circuit 1 in the non-isolated positive and negative voltage supply circuit of this embodiment is as follows: The input voltage is 24V with reference to GND, that is, the input positive terminal is 24V and the input reference ground is GND. The input voltage 24V generates a voltage of +15V at both ends of capacitor C4, capacitor C5, and capacitor C6 through the first DCDC chip U1, diode D2, and inductor L1, that is, the output positive terminal is +15V and the output reference ground is GND.
[0037] The working process of the negative voltage output circuit 2 in the non-isolated positive and negative voltage supply circuit of this embodiment is as follows: The input voltage +15V is referenced to -15V, that is, the input positive terminal is +15V and the input reference ground is -15V. The input voltage +15V generates a voltage of -15V at both ends of capacitor C13, capacitor C14, and capacitor C15 through the second DCDC chip U2, diode D4, and inductor L2, that is, the output positive terminal is GND and the output reference ground is -1�V.
[0038] The negative voltage output circuit 2 realizes the replication of the topological structure and devices of the buck output circuit 1 by taking -15V as the reference ground.
[0039] When supplying power to the positive and negative voltage supply device 3, +15V and -15V are used as the first input terminal and the second input terminal respectively and both are referenced to GND to ensure the normal and stable operation of the positive and negative voltage supply device 3.
[0040] The non-isolated positive and negative power supply circuit provided by the present utility model has exactly the same topological structure and devices for the buck output circuit and the negative voltage output circuit. By changing the grounding network and cascading the same circuit modules, the functions of positive and negative output voltages are realized, thus having the advantages of high modularity, significantly reducing the types of components, and lowering the procurement cost. At the same time, because a non-isolated circuit is used, the circuit design is simple, the overall volume is small, the conversion efficiency is high, and the response speed to load mutations is faster.
[0041] The above-described embodiments merely represent several implementation manners of the present utility model, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the appended claims.
Claims
1. A non-isolated positive and negative power supply circuit, characterized in that, Comprising: Step-down output circuit, negative voltage output circuit, positive and negative voltage supply device; The input end of the step-down output circuit is electrically connected to the +24V power supply, and the output end of the step-down output circuit is electrically connected to the input end of the negative voltage output circuit and the first input end of the positive and negative voltage supply device; the output end of the negative voltage output circuit is electrically connected to the second input end of the positive and negative voltage supply device; The step-down output circuit and the negative voltage output circuit are circuit modules with the same components.
2. The non-isolated positive and negative power supply circuit according to claim 1, wherein Each circuit module includes: a DCDC chip and an input filter circuit, an output filter circuit, a feedback regulation circuit, a loop compensation circuit, a freewheeling circuit, and a protection circuit that are electrically connected to the DCDC chip.
3. The non-isolated positive and negative power supply circuit according to claim 2, wherein The input filter circuit in the step-down output circuit is electrically connected to the +24V power supply, the feedback regulation circuit in the step-down output circuit is electrically connected to the +15V voltage, the output filter circuit in the step-down output circuit is electrically connected to the +15V voltage and the input filter circuit in the negative voltage output circuit, the feedback regulation circuit in the negative voltage output circuit is electrically connected to the -15V voltage, and the output filter circuit in the negative voltage output circuit is electrically connected to the -15V voltage.
4. The non-isolated positive and negative power supply circuit according to claim 3, characterized in that, The input filter circuit includes: three capacitors connected in parallel.
5. The non-isolated positive and negative power supply circuit according to claim 4, wherein, The output filter circuit includes: an inductor and three capacitors connected in parallel.
6. The non-isolated positive and negative power supply circuit according to claim 5, wherein The feedback regulation circuit includes: two resistors and a capacitor.
7. The non-isolated positive and negative power supply circuit according to claim 6, wherein, The loop compensation circuit includes: two capacitors and a resistor.
8. The non-isolated positive and negative power supply circuit according to claim 7, characterized in that, Both the freewheeling circuit and the protection circuit include: a diode.