A constant current source power drive circuit

Abstract

The present application provides a constant current source power driving circuit, comprising a first circuit having a second input terminal and a first output terminal; the second input terminal is used to input a first driving signal, and the first output terminal is used to output the first signal; a second circuit having a third input terminal and a second output terminal, after the first signal passes through the second circuit, the second output terminal outputs the second signal; a third circuit, the third circuit has a fourth input terminal and a third output terminal, after the second signal passes through the third circuit, the third output terminal outputs the third signal; and the third output terminal outputs a first current, the first current is used to drive a load; the third signal and an externally input control signal form a first driving signal, and the value of the first current is linearly proportional to the voltage value of the control signal; the magnitude of the first current can be adjusted by adjusting the voltage value of the control signal, forming an adjustable driving circuit with constant power, thereby improving the applicability of the driving circuit.

Description

Technical Field

[0001] The present application relates to the field of electrical technology, and in particular to a constant current source power drive circuit. Background Art

[0002] In recent years, with the development of science and technology, power electronic products have entered more and more households, greatly facilitating our lives. As people's living standards improve, they also put forward requirements for power electronics to be more high-frequency, miniaturized, high-power density, wide-range output and constant power.

[0003] There are many ways to implement the existing constant current source drive output circuit, and the driving capabilities of the constant current source drive output circuit are also different. However, the output current of the current drive circuit cannot be adjusted and has poor adaptability. Summary of the invention

[0004] In view of the above defects or deficiencies in the prior art, the present application aims to provide a constant current source power driving circuit, comprising:

[0005] A first circuit, the first circuit having a second input terminal and a first output terminal; the second input terminal is used to input a first drive signal, and the first output terminal is used to output a first signal;

[0006] a second circuit, wherein the second circuit has a third input terminal and a second output terminal, the third input terminal is electrically connected to the first output terminal, and after the first signal passes through the second circuit, the second output terminal outputs a second signal;

[0007] a third circuit, wherein the third circuit has a fourth input terminal and a third output terminal, the third output terminal is electrically connected to the second input terminal, and after the second signal passes through the third circuit, the third output terminal outputs a third signal; and the third output terminal outputs a first current, and the first current is used to drive a load;

[0008] The third signal and an externally input control signal form the first driving signal, and the value of the first current is linearly proportional to the voltage value of the control signal.

[0009] According to the technical solution provided in the embodiment of the present application, the second input end is connected to a first feedback resistor on the side away from the first output end, the first feedback resistor is on the side away from the second input end as a first input end, and the first input end is used to input the control signal.

[0010] According to the technical solution provided in the embodiment of the present application, the first circuit includes an operational amplifier component, the positive power supply terminal of the operational amplifier component is connected to the first power supply component, and the negative power supply terminal thereof is grounded, the positive input terminal of the operational amplifier component is grounded, and the negative input terminal is electrically connected to the second input terminal for inputting the first drive signal; the output terminal of the operational amplifier component is electrically connected to the third input terminal.

[0011] According to the technical solution provided in the embodiment of the present application, the second circuit includes a PMOS tube, the source of the PMOS tube is connected to the second power supply component, the gate thereof is electrically connected to the third input terminal, and the drain thereof is the second output terminal.

[0012] According to the technical solution provided in the embodiment of the present application, the third circuit includes a sampling resistor, one end of the sampling resistor is electrically connected to the fourth input end, and the other end is electrically connected to the third output end; the third output end is electrically connected to the second input end.

[0013] According to the technical solution provided in the embodiment of the present application, the first circuit also includes a first filter component having one end electrically connected to the first power supply component, the other end of the first filter component is grounded, and also includes a second filter component having one end electrically connected to the second input end, the other end of the second filter component is electrically connected to the first output end.

[0014] According to the technical solution provided in the embodiment of the present application, the third output terminal is connected to a second feedback resistor, and the second feedback resistor is away from the third output terminal and electrically connected to the second input terminal.

[0015] According to the technical solution provided in the embodiment of the present application, the third circuit also includes a third feedback resistor having one end electrically connected to the second output end, and the other end of the third feedback resistor is electrically connected to the positive input end of the operational amplifier component; and also includes a fourth feedback resistor electrically connected to the third feedback resistor away from the second output end, and the fourth feedback resistor is grounded away from the end of the third feedback resistor.

[0016] According to the technical solution provided in the embodiment of the present application, the sampling resistor is connected to an anti-reverse diode on the side away from the fourth input terminal, and the anti-reverse diode is connected to the load on the side away from the third output terminal.

[0017] According to the technical solution provided in the embodiment of the present application, a TVS tube is connected to the anti-reverse diode away from the third output end, and the TVS tube is grounded away from the end of the anti-reverse diode.

[0018] In summary, the present application proposes a constant current source power driving circuit, wherein the first driving signal forms a first signal after entering the first circuit, the first signal forms a second signal after entering the second circuit, and the second signal forms a third signal after entering the third circuit. The third signal and the external input control signal form the first driving signal, and the third signal forms a feedback signal as the input of the first circuit, thereby forming a closed-loop control. The first current entering the load is linearly proportional to the voltage value of the external input control signal. The magnitude of the first current can be adjusted by adjusting the voltage value of the control signal, thereby forming an adjustable constant power driving circuit, thereby improving the applicability of the driving circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A structural schematic diagram of a constant current source power drive circuit provided in an embodiment of the present application;

[0020] Figure 2 A circuit diagram of a constant current source power drive circuit provided in an embodiment of the present application.

[0021] The text annotations in the figure represent:

[0022] 100, first circuit; 101, second circuit; 102, third circuit; 103, load;

[0023] 201, first input terminal; 202, second input terminal; 203, third input terminal; 204, fourth input terminal;

[0024] 301, first output end; 302, second output end; 303, third output end;

[0025] 401, operational amplifier component; 402, PMOS tube;

[0026] 501, sampling resistor; 502, first feedback resistor; 503, second feedback resistor; 504, third feedback resistor; 505, fourth feedback resistor;

[0027] 601, a first filter component; 602, a second filter component;

[0028] 701, a third adjusting resistor; 702, a fourth adjusting resistor;

[0029] 801, anti-reverse diode; 802, TVS tube. DETAILED DESCRIPTION

[0030] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0031] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] As mentioned in the background technology, in view of the problems in the prior art, the present application proposes a constant current source power driving circuit, comprising:

[0033] A first circuit 100, wherein the first circuit 100 has a second input terminal 202 and a first output terminal 301; the second input terminal is used to input a first driving signal, and the first output terminal 301 is used to output a first signal;

[0034] A second circuit 101, wherein the second circuit 101 has a third input terminal 203 and a second output terminal 302, wherein the third input terminal 203 is electrically connected to the first output terminal 301, and after the first signal passes through the second circuit 101, the second output terminal 302 outputs a second signal;

[0035] A third circuit 102, wherein the third circuit 102 has a fourth input terminal 204 and a third output terminal 303, wherein the third output terminal 303 is electrically connected to the second input terminal 202, and after the second signal passes through the third circuit 102, the third output terminal 303 outputs a third signal; and the third output terminal 303 outputs a first current, and the first current is used to drive the load 103;

[0036] The third signal and the externally input control signal form the first drive signal, and the value of the first current is linearly proportional to the voltage value of the control signal; specifically, the first drive signal forms the first signal after entering the first circuit 100, the first signal forms the second signal after entering the second circuit 101, and the second signal forms the third signal after entering the third circuit 102. The third signal and the externally input control signal form the first drive signal, and the third signal forms a feedback signal as the input of the first circuit 100, forming a closed-loop control, and the first current entering the load 103 is linearly proportional to the voltage value of the externally input control signal. The magnitude of the first current can be adjusted by adjusting the voltage value of the control signal, forming an adjustable drive circuit with constant power.

[0037] Furthermore, a first feedback resistor 502 is connected to the side of the second input terminal 202 away from the first output terminal 301, and the end of the first feedback resistor 502 away from the second input terminal 202 is the first input terminal 201, and the first input terminal 201 is used to input the control signal; optionally, the first feedback resistor 502 adopts a high-precision and low-temperature drift resistor to improve the output accuracy of the first current in various application environments; its resistance value can be selected according to the output value of the first current in different application scenarios.

[0038] Furthermore, the first circuit 100 includes an operational amplifier component 401, the positive power supply terminal of the operational amplifier component 401 is connected to the first power supply component, and the negative power supply terminal thereof is grounded; the positive input terminal of the operational amplifier component 401 is grounded, and the negative input terminal is electrically connected to the second output terminal 202 for inputting the first drive signal; the output terminal of the operational amplifier component 401 is electrically connected to the third input terminal 203; wherein the operational amplifier component 401 is an operational amplifier, and optionally, a compact operational amplifier is selected, and the first power supply component can provide a 5-28V DC power supply.

[0039] Further, the second circuit 101 includes a PMOS tube 402, the source of the PMOS tube 402 is connected to the second power supply component, the gate thereof is electrically connected to the third input terminal 203, and the drain thereof is the second output terminal 302; wherein, the PMOS tube 402 is selected according to the rated value of the first output current and the parameters of the PMOS tube 402 meet the requirements; the first signal is input to the gate of the PMOS tube 402, and the second signal is output from the drain through the voltage drop of the PMOS tube 402, and optionally, the second power supply component can provide a 5-28V DC power supply.

[0040] Further, the third circuit 102 includes a sampling resistor 501, one end of the sampling resistor is electrically connected to the fourth input terminal 204, and the other end is electrically connected to the third output terminal 303; the third output terminal 303 is electrically connected to the second input terminal 202; optionally, the sampling resistor 501 is a high-precision and low-temperature drift sampling resistor to improve the output accuracy of the first current under various application environments; the second signal is input to the sampling resistor 501 to form the third signal, and the third signal is fed back to the second input terminal 202, and together with the external input control signal, forms the first drive signal.

[0041] Furthermore, the first circuit 100 also includes a first filter component 601 having one end electrically connected to the first power supply component, and the other end of the first filter component 601 is grounded; it also includes a second filter component 602 having one end electrically connected to the second input terminal 202, and the other end of the second filter component 602 is electrically connected to the first output terminal 301; optionally, the first filter component 601 is a capacitor C1, and the second filter component 602 is a capacitor C2, and the first filter component 601 and the second filter component 602 are used to perform filtering to improve the accuracy of regulation.

[0042] Furthermore, the third output terminal 303 is connected to a second feedback resistor 503, and the second feedback resistor 503 is electrically connected to the second input terminal 202 away from the third output terminal 303. Optionally, the second feedback resistor 503 adopts a high-precision and low-temperature drift resistor, and the third signal enters the second input terminal 202 after passing through the second feedback resistor 503.

[0043] Further, the third circuit 102 further includes a third feedback resistor 504 having one end electrically connected to the second output end 302, and the other end of the third feedback resistor 504 being electrically connected to the positive input end of the operational amplifier component 401; and further includes a fourth feedback resistor 505 electrically connected to the side of the third feedback resistor 504 away from the second output end 302, and the fourth feedback resistor 505 being grounded away from the third feedback resistor 504; wherein, by sampling the voltage across the sampling resistor 501, and by the first feedback resistor 502, the second feedback resistor 503, the third feedback resistor 504, and the fourth feedback resistor 505 forming a feedback circuit together, and forming a regulating circuit together with the control signal to drive the PMOS tube to be turned on and off. By adjusting the resistance value of the sampling resistor 501 and the resistance value in the feedback circuit, the voltage of the control signal and the output current can be flexibly and linearly regulated, and the output of high-power current can be achieved by selecting the high-power PMOS tube 402.

[0044] In addition, the second power supply component is connected to a first regulating resistor 701, and the first regulating resistor 701 is electrically connected to the third input terminal 203 away from the second power supply component; optionally, the first regulating resistor 701 adopts a high-precision low-temperature drift resistor, and the first regulating resistor 701 can adjust the voltage input to the source of the PMOS tube 402. In addition, the first output terminal 301 is connected to a second regulating resistor 702 away from the output terminal of the operational amplifier, and the second regulating resistor 702 is electrically connected to the first regulating resistor 701 away from the first output terminal 301 and the second power supply component.

[0045] The first current and the voltage value of the control signal are in linear proportional relationship, and the proportionality coefficient is determined by the resistance values ​​in the feedback circuit; Figure 2 The following formula can be obtained:

[0046]

[0047] Wherein, V2 is the voltage of the third output terminal 303, V IN is the control signal voltage; R1 is the resistance of the second feedback resistor 503, R4 is the resistance of the first feedback resistor 502, I is the current value of the first current, R6 is the resistance of the sampling resistor 501, R7 is the resistance of the fourth feedback resistor 505, and R5 is the resistance of the third feedback resistor 504;

[0048] Let R1=R5, R4=R7, then we get the following formula:

[0049]

[0050] In some specific scenarios, if R6 is set to 1, the following formula is obtained:

[0051]

[0052] Therefore, it can be seen from formula (3) that the first current and the voltage of the control signal are in a linear relationship.

[0053] Furthermore, the sampling resistor 501 is connected to a reverse diode 801 on the side away from the fourth input terminal 204, and the reverse diode 801 is connected to the load 103 on the side away from the third output terminal 303; wherein the reverse diode 801 is used to prevent external reverse voltage from damaging the internal driving circuit.

[0054] Furthermore, a TVS tube 802 is connected to the side of the anti-reverse diode 801 away from the third output terminal 303, and the TVS tube 802 is grounded away from the end of the anti-reverse diode 801; wherein the TVS tube 802 is used to prevent external large voltage from damaging the power output channel.

[0055] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and its core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A constant current source power driving circuit, characterized in that: include: A first circuit (100), the first circuit (100) having a second input terminal (202) and a first output terminal (301); the second input terminal (202) is used to input a first drive signal, and the first output terminal (301) is used to output a first signal; a second circuit (101), wherein the second circuit (101) has a third input terminal (203) and a second output terminal (302), the third input terminal (203) being electrically connected to the first output terminal (301), and after the first signal passes through the second circuit (101), the second output terminal (302) outputs a second signal; A third circuit (102), the third circuit (102) having a fourth input terminal (204) and a third output terminal (303), the third output terminal (303) being electrically connected to the second input terminal (202), the third output terminal (303) outputting a third signal after the second signal passes through the third circuit (102); and the third output terminal (303) outputting a first current, the first current being used to drive a load (103); The third signal and an externally input control signal form the first driving signal, and the value of the first current is linearly proportional to the voltage value of the control signal; The side of the second input end (202) away from the first output end (301) is connected to a first feedback resistor (502); the side of the first feedback resistor (502) away from the second input end (202) is a first input end (201); the first input end (201) is used to input the control signal; The first circuit (100) comprises an operational amplifier component (401), the positive power supply terminal of the operational amplifier component (401) is connected to the first power supply component, the negative power supply terminal thereof is grounded, the positive input terminal of the operational amplifier component (401) is grounded, and the negative input terminal is electrically connected to the second input terminal (202) for inputting the first drive signal; the output terminal of the operational amplifier component (401) is electrically connected to the third input terminal (203); The second circuit (101) comprises a PMOS tube (402), the source of the PMOS tube (402) is connected to the second power supply component, the gate of the PMOS tube (402) is electrically connected to the third input terminal (203), and the drain of the PMOS tube (402) is the second output terminal (302); The third circuit (102) comprises a sampling resistor (501), one end of the sampling resistor (501) being electrically connected to the fourth input end (204), and the other end of the sampling resistor (501) being electrically connected to the third output end (303); the third output end (303) being electrically connected to the second input end (202); The first circuit (100) further comprises a first filter component (601) having one end electrically connected to the first power supply component, and the other end of the first filter component (601) is grounded; and further comprises a second filter component (602) having one end electrically connected to the second input end (202), and the other end of the second filter component (602) is electrically connected to the first output end (301); The third output terminal (303) is connected to a second feedback resistor (503), and the second feedback resistor (503) is away from the third output terminal (303) and electrically connected to the second input terminal (202); The third circuit (102) further comprises a third feedback resistor (504) having one end electrically connected to the second output end (302), and the other end of the third feedback resistor (504) being electrically connected to the positive input end of the operational amplifier component (401); and further comprises a fourth feedback resistor (505) electrically connected to the side of the third feedback resistor (504) away from the second output end (302), and the end of the fourth feedback resistor (505) away from the third feedback resistor (504) is grounded; The sampling resistor (501) is connected to an anti-reverse diode (801) on the side away from the fourth input terminal (204), and the anti-reverse diode (801) is connected to the load (103) on the side away from the third output terminal (303); The side of the anti-reverse diode (801) away from the third output end (303) is connected to a TVS tube (802), and the end of the TVS tube (802) away from the anti-reverse diode (801) is grounded.

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