A bidirectional constant voltage power supply circuit

Abstract

The present application relates to the field of load constant voltage power supply, specifically, to a bidirectional constant voltage power supply circuit, including: a voltage regulating component; a first MOS tube, a first end of which is connected to the power supply voltage, a second end of which is connected to the first end of the load and is grounded through the voltage regulating component; a second MOS tube, a first end of which is connected to the power supply voltage, a second end of which is connected to the second end of the load and is grounded through the voltage regulating component; a control module, a first end and a second end of which are respectively connected to the third end of the first MOS tube and the third end of the second MOS tube. The bidirectional constant voltage power supply circuit of the present application can solve the problem that the existing load positive and negative bidirectional constant voltage power supply device cannot have the advantages of low cost, low noise and small circuit board area, and has the advantages of small circuit board area, low cost and small noise.

Description

Technical Field

[0001] The present application relates to the field of load constant voltage power supply, and in particular, to a bidirectional constant voltage power supply circuit. Background Art

[0002] Existing devices for providing forward and reverse bidirectional constant voltage power to loads are generally a combination of two power supply systems for providing forward and reverse power to the loads respectively, or a double-gate relay for switching the energized circuit to provide forward and reverse bidirectional constant voltage power to the loads.

[0003] However, the method based on two power supply systems has a high cost, and the method based on double-gate relay power supply has the problem of noise caused by relay contact switching when switching the power supply direction. In addition, both of the above methods have the problem of occupying a large circuit board area. Therefore, the existing load positive and negative bidirectional constant voltage power supply device cannot have the advantages of low cost, low noise and small circuit board area.

[0004] Therefore, the existing technology needs to be improved and developed. Summary of the invention

[0005] The purpose of the present application is to provide a bidirectional constant voltage power supply circuit, aiming to solve the problem that the existing load positive and negative bidirectional constant voltage power supply device cannot have the advantages of low cost, low noise and small circuit board area.

[0006] The present application provides a bidirectional constant voltage power supply circuit, which is used to provide bidirectional constant voltage power supply to a load, including: A voltage regulating component for regulating the voltage applied to the load; A first MOS tube, a first end of which is connected to the power supply voltage, and a second end of which is connected to the first end of the load and is grounded through a voltage regulating component; A second MOS tube, a first end of which is connected to the power supply voltage, a second end of which is connected to the second end of the load and is grounded through the voltage regulating component; A control module, whose first end and second end are respectively connected to the third end of the first MOS tube and the third end of the second MOS tube, is used to output complementary voltage signals to the third end of the first MOS tube and the third end of the second MOS tube respectively, so as to control one of the first MOS tube and the second MOS tube to be turned on and the other to be turned off.

[0007] The bidirectional constant voltage power supply circuit provided in the present application can realize switching power supply only by controlling the MOS tube to be turned on or off based on the control module, and has the advantages of occupying a small circuit board area, low cost and generating less noise.

[0008] Optionally, the voltage regulating component includes: A third MOS tube, a first end of which is connected to the second end of the first MOS tube, and a second end of which is grounded; a fourth MOS tube, a first end of which is connected to the second end of the second MOS tube, and a second end of which is grounded; The bidirectional constant voltage power supply circuit also includes: A freewheeling component, wherein the first end and the second end of the load are respectively connected to the first end of the second MOS tube and the first end of the first MOS tube through the freewheeling component, and the freewheeling component is used to guide the current of the first end of the load to the first end of the second MOS tube when the third MOS tube is turned off, and to guide the current of the second end of the load to the first end of the first MOS tube when the fourth MOS tube is turned off; The third end and the fourth end of the control module are connected to the third end of the third MOS tube and the third end of the fourth MOS tube respectively, and are also used to input a PWM signal to the third end of the third MOS tube or the third end of the fourth MOS tube to control the third MOS tube or the fourth MOS tube to be turned on and off.

[0009] In this implementation, the bidirectional constant voltage power supply circuit of the present application can realize continuous power supply to the load and can realize adjustable load power.

[0010] Optionally, the freewheeling component includes: An inductor, one end of which is connected to the second end of the first MOS tube, and the other end of which is connected to the first end of the load; A first freewheeling element, whose input end is connected to one end of the inductor, and whose second end is connected to the first end of the second MOS tube, is used to cooperate with the inductor to make the current output from one end of the inductor change smoothly; The second freewheeling element has an input end connected to the second end of the load and a second end connected to the first end of the first MOS tube, and is used to cooperate with the inductor to make the current flowing out of the second end of the load change smoothly.

[0011] In this embodiment, the bidirectional constant-voltage power supply circuit of the present application is provided with an inductor, a first follow-up device and a second follow-up device, which can generate current when the third MOS tube is turned off or the fourth MOS tube is turned off so that a loop exists in the bidirectional constant-voltage power supply circuit, thereby realizing continuous power supply to the load; and the present application is provided with an inductor, a first follow-up device and a second follow-up device, which can make the current flowing out of one end of the inductor or the second end of the load change smoothly, thereby protecting the electrical components in the bidirectional constant-voltage power supply circuit.

[0012] Optionally, the first freewheeling element and the second freewheeling element are both freewheeling diodes.

[0013] Optionally, the third MOS transistor and the fourth MOS transistor are both NMOS transistors.

[0014] Optionally, the bidirectional constant voltage power supply circuit further includes: a first resistor; a second resistor, the supply voltage is grounded through the first resistor and the second resistor; The fifth end of the control module is connected to the connection point between the first resistor and the second resistor, and is also used to perform voltage detection on the fifth end to detect the supply voltage.

[0015] Optionally, the bidirectional constant voltage power supply circuit further includes: The third resistor; a fourth resistor, a first end of the load is grounded through the third resistor and the fourth resistor; The sixth end of the control module is connected to the connection point of the third resistor and the fourth resistor, and the seventh end is connected to the second end of the third MOS tube and the second end of the fourth MOS tube. The control module is also used to perform voltage detection on the sixth end and current detection on the seventh end to cooperate with the fifth end to perform power detection on the load.

[0016] Optionally, the first MOS transistor and the second MOS transistor are both PMOS transistors.

[0017] Optionally, the third end of the first MOS tube is connected to the first end, and the third end of the second MOS tube is connected to the first end; The bidirectional constant voltage power supply circuit also includes: A first triode, whose collector is connected to the third end of the first MOS tube, whose emitter is grounded, whose base is connected to the first end of the control module, and the third end of the first MOS tube is connected to the first end of the control module through the first triode; The second triode has a collector connected to the third end of the second MOS tube, an emitter connected to the ground, and a base connected to the second end of the control module. The third end of the second MOS tube is connected to the second end of the control module through the second triode.

[0018] Optionally, the bidirectional constant voltage power supply circuit further includes: Capacitor, connected in parallel with the load.

[0019] From the above, it can be seen that the present application provides a bidirectional constant voltage power supply circuit, which can realize switching power supply only by controlling the MOS tube to be turned on or off based on the control module. It has the advantages of occupying a small circuit board area, low cost and generating less noise.

[0020] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A circuit diagram of a bidirectional constant voltage power supply circuit provided in an embodiment of the present application.

[0022] Figure 2A circuit diagram of a freewheeling component provided in an embodiment of the present application.

[0023] Figure 3 A schematic diagram of the access points of various terminals of the control module in the bidirectional constant voltage power supply circuit provided in an embodiment of the present application.

[0024] Figure 4 A schematic diagram of the structure of the control module provided in an embodiment of the present application.

[0025] Figure 5 A circuit diagram of a local circuit in which a first resistor and a second resistor are located according to an embodiment of the present application.

[0026] Figure 6 A circuit diagram of a local circuit where the third resistor and the fourth resistor are located according to an embodiment of the present application.

[0027] Explanation of reference numerals: C, capacitor; L, inductor; N1, third MOS tube; N2, fourth MOS tube; P1, first MOS tube; P2, second MOS tube; Q1, first triode; Q2, second triode; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; R9, ninth resistor; R10, tenth resistor; R11, eleventh resistor; R12, twelfth resistor; R13, thirteenth resistor; VCC, power supply voltage; 1, load; 2, control module; 3, freewheeling component; 31, first freewheeling component; 32, second freewheeling component; 4, voltage regulating component. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0029] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0030] like Figure 1 , Figure 3 and Figure 4 As shown, the present application provides a bidirectional constant voltage power supply circuit for providing bidirectional constant voltage power supply to a load 1, including: A voltage regulating component 4, used for regulating the voltage applied to the load 1; A first MOS transistor P1, a first end of which is connected to the power supply voltage VCC, and a second end of which is connected to the first end of the load 1 and is grounded through the voltage regulating component 4; A second MOS transistor P2, a first end of which is connected to the power supply voltage VCC, and a second end of which is connected to the second end of the load 1 and is grounded through the voltage regulating component 4; The control module 2 has a first end and a second end connected to the third end of the first MOS transistor P1 and the third end of the second MOS transistor P2, respectively, and is used to output complementary voltage signals to the third end of the first MOS transistor P1 and the third end of the second MOS transistor P2, respectively, so as to control one of the first MOS transistor P1 and the second MOS transistor P2 to be turned on and the other to be turned off.

[0031] Specifically, Figure 4 The B1 and B2 in Figure 3 Connect B1 and B2 in the figure.

[0032] More specifically, the process of inputting a voltage to the first terminal of the load 1 is the forward power supply process of the load 1 , and the process of inputting a voltage to the second terminal of the load 1 is the reverse power supply process of the load 1 .

[0033] More specifically, the first MOS transistor P1 and the second MOS transistor P2 are of the same type.

[0034] More specifically, in the present application, two voltage signals are complementary, which means that one of the two voltage signals is at a high level, and the other voltage signal is at a low level.

[0035] More specifically, the control module 2 may include a micro control unit, or may include an existing control device that can output different voltage signals and has a relatively small size.

[0036] More specifically, when the first MOS tube P1 is turned on and the second MOS tube P2 is turned off, the first end of the load 1 inputs the power supply voltage VCC, and the second end outputs a voltage to the ground. At this time, the bidirectional constant voltage power supply circuit supplies forward power to the load 1; when the second MOS tube P2 is turned on and the first MOS tube P1 is turned off, the second end of the load 1 inputs the power supply voltage VCC, and the first end outputs a voltage to the ground. At this time, the bidirectional constant voltage power supply circuit supplies reverse power to the load 1.

[0037] More specifically, the method for adjusting the voltage applied to the load based on the voltage regulating component 4 can be to adjust the resistance value of the adjustable resistor included in the voltage regulating component 4 to change its voltage division, thereby changing the voltage division of the load to adjust the voltage applied to the load, or other existing methods that can adjust the voltage applied to the load based on the voltage regulating component 4.

[0038] More specifically, the bidirectional constant voltage power supply circuit of the present application only needs one circuit to realize the positive and negative bidirectional constant voltage power supply of load 1, and only needs to control the MOS tube to be turned on or off based on the control module 2 to realize the switching power supply. The MOS tube is small in size, low in cost and generates less noise during operation. Therefore, the bidirectional constant voltage power supply circuit of the present application occupies a small circuit board area, has a low cost and generates less noise.

[0039] The bidirectional constant voltage power supply circuit provided in the present application can realize switching power supply only by controlling the MOS tube to be turned on or off based on the control module 2, and has the advantages of occupying a small circuit board area, low cost and generating less noise.

[0040] In this implementation, the present application sets up a micro control unit, which can further improve the degree of circuit integration, thereby further reducing the area of ​​the circuit board occupied by the bidirectional constant voltage power supply circuit.

[0041] In some preferred embodiments, the voltage regulating assembly 4 includes: A third MOS transistor N1, a first end of which is connected to the second end of the first MOS transistor P1, and a second end of which is grounded; A fourth MOS transistor N2, a first end of which is connected to the second end of the second MOS transistor P2, and a second end of which is grounded; The bidirectional constant voltage power supply circuit also includes: A freewheeling component 3, wherein the first end and the second end of the load 1 are respectively connected to the first end of the second MOS transistor P2 and the first end of the first MOS transistor P1 through the freewheeling component 3, and the freewheeling component 3 is used to guide the current of the first end of the load 1 to the first end of the second MOS transistor P2 when the third MOS transistor N1 is turned off, and to guide the current of the second end of the load 1 to the first end of the first MOS transistor P1 when the fourth MOS transistor N2 is turned off; The third end and the fourth end of the control module 2 are respectively connected to the third end of the third MOS tube N1 and the third end of the fourth MOS tube N2, and are also used to input a PWM signal to the third end of the third MOS tube N1 or the third end of the fourth MOS tube N2 to control the third MOS tube N1 or the fourth MOS tube N2 to be turned on and off.

[0042] Specifically, Figure 4 The B3 and B4 in Figure 3 Connect at B3 and B4 in the figure.

[0043] More specifically, when the first MOS transistor P1 is turned on and the second MOS transistor P2 is turned off, and the bidirectional constant voltage power supply circuit supplies forward power to the load 1, when the fourth MOS transistor N2 is turned on, the current flows through the first MOS transistor P1, the load 1, the fourth MOS transistor N2 and flows to the ground; when the fourth MOS transistor N2 is turned off, the freewheeling component 3 diverts the current at the second end of the load 1 to the first end of the first MOS transistor P1, and the current flows through the first MOS transistor P1 and flows back to the first end of the load 1. Similarly, when the second MOS transistor P2 is turned on and the first MOS transistor P1 is turned off, and the bidirectional constant voltage power supply circuit supplies reverse power to the load 1, when the third MOS transistor N1 is turned on, the current flows through the second MOS transistor P2, the load 1, the third MOS transistor N1 and flows to the ground; when the third MOS transistor N1 is turned off, the freewheeling component 3 diverts the current at the first end of the load 1 to the first end of the second MOS transistor P2, and the current flows through the second MOS transistor P2 and flows back to the second end of the load 1. Therefore, no matter whether the load 1 is powered forward or reversely, no matter whether the third MOS tube N1 and the fourth MOS tube N2 are turned on or off, there is a loop in the bidirectional constant voltage power supply circuit, so that the load 1 can be continuously powered. In addition, the bidirectional constant voltage power supply circuit of the present application controls the conduction and cutoff of the third MOS tube N1 or the fourth MOS tube N2 based on the PWM signal, and can adjust the power of the load 1 by adjusting the duty cycle of the PWM signal.

[0044] In this implementation, the bidirectional constant voltage power supply circuit of the present application can realize continuous power supply to the load 1 and can realize adjustable power of the load 1.

[0045] Preferably, the third end of the third MOS tube N1 and the third end of the fourth MOS tube N2 are connected to the third end and the fourth end of the control module 2 through the tenth resistor R10 and the twelfth resistor R12 respectively, and are grounded through the eleventh resistor R11 and the thirteenth resistor R13 respectively.

[0046] like Figure 2 As shown, in some preferred embodiments, the freewheeling component 3 includes: An inductor L, one end of which is connected to the second end of the first MOS transistor P1, and the other end of which is connected to the first end of the load 1; A first freewheeling element 31, whose input end is connected to one end of the inductor L, and whose second end is connected to the first end of the second MOS transistor P2, is used to cooperate with the inductor L to make the current flowing out of one end of the inductor L change smoothly; The second freewheeling element 32 has an input end connected to the second end of the load 1 and a second end connected to the first end of the first MOS transistor P1, and is used to cooperate with the inductor L to make the current flowing out of the second end of the load 1 change smoothly.

[0047] Specifically, when the first MOS transistor P1 is turned on and the second MOS transistor P2 is turned off, and the bidirectional constant voltage power supply circuit supplies forward power to the load 1, when the fourth MOS transistor N2 is turned on, the current flows through the first MOS transistor P1, the inductor L, the load 1, the fourth MOS transistor N2 and flows to the ground; when the fourth MOS transistor N2 is turned off, the inductor L generates a current, and the current flows through the load 1, the second follow-up component 32 and the first MOS transistor P1 and flows back to the inductor L. When the first MOS transistor P1 is turned off and the second MOS transistor P2 is turned on, and the bidirectional constant voltage power supply circuit supplies reverse power to the load 1, when the third MOS transistor N1 is turned on, the current flows through the second MOS transistor P2, the load 1, the inductor L, the third MOS transistor N1 and flows to the ground; when the third MOS transistor N1 is turned off, the inductor L generates a current, and the current flows through the first follow-up component 31, the second MOS transistor P2 and the load 1 and flows back to the inductor L. Therefore, in this embodiment, the bidirectional constant-voltage power supply circuit of the present application is provided with an inductor L, a first follow-up component 31 and a second follow-up component 32, which can generate a current when the third MOS tube N1 is turned off or the fourth MOS tube N2 is turned off so that a loop exists in the bidirectional constant-voltage power supply circuit, thereby realizing continuous power supply to the load 1; and the present application is provided with an inductor L, a first follow-up component 31 and a second follow-up component 32, which can make the current flowing out of one end of the inductor L or the second end of the load 1 change smoothly, thereby protecting the electrical components in the bidirectional constant-voltage power supply circuit.

[0048] In some preferred embodiments, the first freewheeling element 31 and the second freewheeling element 31 are both freewheeling diodes. Specifically, when the first MOS transistor P1 is turned on and the second MOS transistor P2 is turned off, and the bidirectional constant voltage power supply circuit supplies forward power to the load 1, when the fourth MOS transistor N2 is turned on, since the first freewheeling component 31 is a freewheeling diode, the current only flows from the branch where the first MOS transistor P1 is located to the inductor L, and does not flow from the branch where the first freewheeling component 31 is located to the inductor L; when the fourth MOS transistor N2 is turned off, the current flowing through the load 1 can flow to the first MOS transistor P1 through the second freewheeling component 32. Similarly, when the first MOS transistor P1 is turned off and the second MOS transistor P2 is turned on, and the bidirectional constant voltage power supply circuit supplies reverse power to the load 1, when the third MOS transistor N1 is turned on, since the second freewheeling component 32 is a freewheeling diode, the current only flows from the branch where the second MOS transistor P2 is located to the load 1, and does not flow from the branch where the second freewheeling component 32 is located to the load 1; when the third MOS transistor N1 is turned off, the current generated by the inductor L can flow to the second MOS transistor P2 through the first freewheeling component 31.

[0049] In this embodiment, the bidirectional constant voltage power supply circuit of the present application sets the first freewheeling element 31 and the second freewheeling element 32 as freewheeling diodes, which can make the current flowing out of one end of the inductor L or the second end of the load 1 change smoothly, thereby protecting the electrical components in the bidirectional constant voltage power supply circuit; and the present application sets a freewheeling diode to ensure that the forward power supply and reverse power supply of the load 1 are respectively controlled by the opening and closing of the first MOS tube P1 and the second MOS tube P2.

[0050] In some preferred implementations, the third MOS transistor N1 and the fourth MOS transistor N2 are both NMOS transistors.

[0051] Specifically, the first end, the second end and the third end of the third MOS transistor N1 and the fourth MOS transistor N2 are the drain, the source and the gate of the respective terminals.

[0052] In this embodiment, the bidirectional constant-voltage power supply circuit of the present application sets the third MOS tube N1 and the fourth MOS tube N2 as NMOS tubes, and can control the third MOS tube N1 or the fourth MOS tube N2 to be turned on when the PWM signal is at a high level, and control the third MOS tube N1 or the fourth MOS tube N2 to be turned off when the PWM signal is at a low level, so as to realize the control of the internal path change of the bidirectional constant-voltage power supply circuit based on the change of the PWM signal level, thereby realizing the power adjustment of the load 1 by adjusting the duty cycle of the PWM signal.

[0053] like Figure 5 As shown, in some preferred embodiments, the bidirectional constant voltage power supply circuit further includes: A first resistor R1; A second resistor R2, a supply voltage VCC is grounded through the first resistor R1 and the second resistor R2; The fifth end of the control module 2 is connected to the connection point between the first resistor R1 and the second resistor R2, and is also used to perform voltage detection on the fifth end to detect the power supply voltage VCC.

[0054] Specifically, Figure 4 B5 in Figure 5 Connect at B5 in.

[0055] More specifically, the ratio of the first resistor R1 to the second resistor R2 is the ratio of the voltage applied to the first resistor R1 to the voltage applied to the second resistor R2, and the sum of the two voltages respectively applied to the first resistor R1 and the second resistor R2 is the voltage value of the power supply voltage VCC. Therefore, it is only necessary to perform voltage detection on the fifth terminal of the control module 2 to determine the voltage applied to the second resistor R2, thereby calculating the voltage value of the power supply voltage VCC and realizing the detection of the power supply voltage VCC.

[0056] In this embodiment, the bidirectional constant voltage power supply circuit of the present application is provided with a first resistor R1 and a second resistor R2, which can detect the power supply voltage VCC and adjust the voltage value of the power supply voltage VCC as needed.

[0057] like Figure 6 As shown, in some preferred embodiments, the bidirectional constant voltage power supply circuit further includes: A third resistor R3; A fourth resistor R4, a first end of the load 1 is grounded through the third resistor R3 and the fourth resistor R4; The sixth end of the control module 2 is connected to the connection point of the third resistor R3 and the fourth resistor R4, and the seventh end is connected to the second end of the third MOS tube N1 and the second end of the fourth MOS tube N2. The control module 2 is also used to perform voltage detection on the sixth end and current detection on the seventh end to cooperate with the fifth end to perform power detection on the load 1.

[0058] Specifically, Figure 4 The B6 and B7 in Figure 6 B6 and Figure 3 Connect to B7 in Figure 3 B0 in the Figure 6 Connect to B0 in .

[0059] More specifically, similar to the principle of power supply voltage VCC detection, the present application performs voltage detection on the sixth terminal of the control module 2, and can determine the voltage applied to the fourth resistor R4, thereby calculating the value of the voltage input to the first terminal of the load 1 or the value of the voltage output from the first terminal of the load 1. During the forward power supply process of the load 1, the value of the voltage applied to the load 1 is the value of the voltage input to the first terminal of the load 1; and during the reverse power supply process of the load 1, the value of the voltage applied to the load 1 is the difference between the voltage value of the power supply voltage VCC and the value of the voltage output from the first terminal of the load 1. Therefore, it is only necessary to perform voltage detection on the fifth and sixth terminals of the control module 2 to calculate the value of the voltage applied to the load 1.

[0060] More specifically, it is only necessary to perform current detection on the seventh terminal of the control module 2 to detect the current flowing through the first MOS tube P1 and the load 1 or the current flowing through the second MOS tube P2 and the load 1, so as to calculate the power of the load 1 in conjunction with the calculated voltage applied to the load 1, thereby realizing power detection of the load 1.

[0061] In this implementation, the bidirectional constant voltage power supply circuit of the present application can realize power detection of the load 1, so as to facilitate power regulation of the load 1 when necessary.

[0062] Preferably, the second end of the third MOS transistor N1 and the second end of the fourth MOS transistor N2 are grounded via a ninth resistor R9.

[0063] In some preferred implementations, the first MOS transistor P1 and the second MOS transistor P2 are both PMOS transistors.

[0064] Specifically, the first end, the second end and the third end of the first MOS transistor P1 and the second MOS transistor P2 are respectively the source, the drain and the gate of the respective terminals.

[0065] In this embodiment, the bidirectional constant voltage power supply circuit of the present application sets the first MOS tube P1 and the second MOS tube P2 as PMOS tubes, and can control the first MOS tube P1 or the second MOS tube P2 to be turned off based on a high level input to the gate of the first MOS tube P1 or the second MOS tube P2, or control the first MOS tube P1 or the second MOS tube P2 to be turned on based on a low level input to the gate of the first MOS tube P1 or the second MOS tube P2, thereby respectively inputting complementary signals to the first MOS tube P1 and the second MOS tube P2 to turn on one and turn off the other.

[0066] In some preferred embodiments, the third end of the first MOS transistor P1 is connected to the first end, and the third end of the second MOS transistor P2 is connected to the first end; The bidirectional constant voltage power supply circuit also includes: A first transistor Q1, whose collector is connected to the third end of the first MOS transistor P1, whose emitter is grounded, and whose base is connected to the first end of the control module 2. The third end of the first MOS transistor P1 is connected to the first end of the control module 2 through the first transistor Q1; The second transistor Q2 has a collector connected to the third end of the second MOS transistor P2, an emitter connected to ground, and a base connected to the second end of the control module 2. The third end of the second MOS transistor P2 is connected to the second end of the control module 2 through the second transistor Q2.

[0067] Specifically, when the control module 2 outputs a low voltage signal to the first transistor Q1, the first transistor Q1 is turned off, the gate of the first MOS transistor P1 inputs the power supply voltage VCC, that is, a high voltage, and the first MOS transistor P1 is turned off; when the control module 2 outputs a high voltage signal to the first transistor Q1, the first transistor Q1 is turned on, the power supply voltage VCC is no longer input to the gate of the first MOS transistor P1, and the first MOS transistor P1 is turned on. Similarly, when the control module 2 outputs a low voltage signal to the second transistor Q2, the second MOS transistor P2 is turned off; when the control module 2 outputs a high voltage signal to the second transistor Q2, the second MOS transistor P2 is turned on.

[0068] More specifically, in order to make the bidirectional constant voltage power supply circuit occupy a small circuit board area, the device structure included in the control module 2 of the present application is generally small and cannot output a higher voltage, but the MOS tube generally needs to be driven based on a higher voltage to achieve low loss. Therefore, in this embodiment, the present application sets a first transistor Q1 and a second transistor Q2, which can make the power supply voltage VCC with a higher voltage value input into the gate of the first MOS tube P1 or the gate of the second MOS tube P2 to cut off the first MOS tube P1 or the second MOS tube P2, or make the power supply voltage VCC no longer input into the gate of the first MOS tube P1 or the gate of the second MOS tube P2 to turn on the first MOS tube P1 or the second MOS tube P2, so that the low-loss operation of the MOS tube can be achieved while freely controlling the first MOS tube P1 and the second MOS tube P2 to be turned on or off.

[0069] Preferably, the third end and the first end of the first MOS transistor P1 are connected via a fifth resistor R5; The third end and the first end of the second MOS tube P2 are connected via a sixth resistor R6; The base of the first transistor Q1 is connected to the first end of the control module 2 through the seventh resistor R7; The base of the second transistor Q2 is connected to the second end of the control module 2 through the eighth resistor R8.

[0070] In some preferred embodiments, the bidirectional constant voltage power supply circuit further includes: Capacitor C is connected in parallel with load 1.

[0071] In this embodiment, the bidirectional constant voltage power supply circuit of the present application is provided with a capacitor C, which can effectively reduce the noise generated by the high-frequency signal in the circuit based on the filtering effect of the capacitor C.

[0072] As can be seen from the above, the present application provides a bidirectional constant voltage power supply circuit, which can realize switching power supply only by controlling the MOS tube to be turned on or off based on the control module 2, and has the advantages of occupying a small circuit board area, low cost and generating less noise.

[0073] In the embodiments provided in the present application, it should be understood that, herein, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0074] The above are only embodiments of the present application and are not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

Claims

1. A bidirectional constant voltage power supply circuit, used for providing bidirectional constant voltage power supply to a load (1), characterized in that: include: A voltage regulating component (4) for regulating the voltage applied to the load (1); A first MOS tube, a first end of which is connected to the power supply voltage, and a second end of which is connected to the first end of the load (1) and is grounded through the voltage regulating component (4); A second MOS tube, a first end of which is connected to the power supply voltage, and a second end of which is connected to the second end of the load (1) and is grounded through the voltage regulating component (4); A control module (2), wherein the first end and the second end are respectively connected to the third end of the first MOS tube and the third end of the second MOS tube, and is used to output complementary voltage signals to the third end of the first MOS tube and the third end of the second MOS tube, respectively, so as to control one of the first MOS tube and the second MOS tube to be turned on and the other to be turned off.

2. A bidirectional constant voltage power supply circuit according to claim 1, characterized in that: The voltage regulating component (4) comprises: A third MOS tube, a first end of which is connected to the second end of the first MOS tube, and a second end of which is grounded; a fourth MOS tube, a first end of which is connected to the second end of the second MOS tube, and a second end of which is grounded; The bidirectional constant voltage power supply circuit also includes: a freewheeling component (3), wherein the first end and the second end of the load (1) are respectively connected to the first end of the second MOS tube and the first end of the first MOS tube through the freewheeling component (3), and the freewheeling component (3) is used to guide the current at the first end of the load (1) to the first end of the second MOS tube when the third MOS tube is turned off, and to guide the current at the second end of the load (1) to the first end of the first MOS tube when the fourth MOS tube is turned off; The third end and the fourth end of the control module (2) are respectively connected to the third end of the third MOS tube and the third end of the fourth MOS tube, and are also used to input a PWM signal to the third end of the third MOS tube or the third end of the fourth MOS tube to control the third MOS tube or the fourth MOS tube to be turned on and off.

3. A bidirectional constant voltage power supply circuit according to claim 2, characterized in that: The freewheeling component (3) comprises: an inductor, one end of which is connected to the second end of the first MOS tube, and the other end of which is connected to the first end of the load (1); A first freewheeling element (31), whose input end is connected to one end of the inductor and whose second end is connected to the first end of the second MOS tube, and is used to cooperate with the inductor to make the current flowing out of one end of the inductor change smoothly; The second freewheeling element (32) has an input end connected to the second end of the load (1), and a second end connected to the first end of the first MOS tube, and is used to cooperate with the inductor to make the current flowing out of the second end of the load (1) change smoothly.

4. A bidirectional constant voltage power supply circuit according to claim 3, characterized in that: The first freewheeling element (31) and the second freewheeling element (31) are both freewheeling diodes.

5. A bidirectional constant voltage power supply circuit according to claim 2, characterized in that: The third MOS tube and the fourth MOS tube are both NMOS tubes.

6. A bidirectional constant voltage power supply circuit according to claim 2, characterized in that: The bidirectional constant voltage power supply circuit also includes: a first resistor; a second resistor, a supply voltage is grounded through the first resistor and the second resistor; The fifth end of the control module (2) is connected to the connection point between the first resistor and the second resistor, and is also used to perform voltage detection on the fifth end to detect the supply voltage.

7. A bidirectional constant voltage power supply circuit according to claim 6, characterized in that: The bidirectional constant voltage power supply circuit also includes: The third resistor; a fourth resistor, wherein the first end of the load (1) is grounded through the third resistor and the fourth resistor; The control module (2) has a sixth end connected to the connection point between the third resistor and the fourth resistor, and a seventh end connected to the second end of the third MOS tube and the second end of the fourth MOS tube. The control module (2) is also used to perform power detection on the load (1) in coordination with the fifth end based on voltage detection on the sixth end and current detection on the seventh end.

8. The bidirectional constant voltage power supply circuit according to claim 1, characterized in that: The first MOS tube and the second MOS tube are both PMOS tubes.

9. A bidirectional constant voltage power supply circuit according to claim 8, characterized in that: The third end of the first MOS tube is connected to the first end, and the third end of the second MOS tube is connected to the first end; The bidirectional constant voltage power supply circuit also includes: A first triode, the collector of which is connected to the third end of the first MOS tube, the emitter of which is grounded, the base of which is connected to the first end of the control module (2), and the third end of the first MOS tube is connected to the first end of the control module (2) through the first triode; A second triode, whose collector is connected to the third end of the second MOS tube, whose emitter is grounded, whose base is connected to the second end of the control module (2), and the third end of the second MOS tube is connected to the second end of the control module (2) through the second triode.

10. The bidirectional constant voltage power supply circuit according to claim 1, characterized in that: The bidirectional constant voltage power supply circuit also includes: A capacitor is connected in parallel with the load (1).

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