A control circuit and control method for constant current source output voltage convex wave

Abstract

The present invention provides a control circuit and control method for a constant current source output voltage convex wave, the processing circuit includes a main control circuit, a constant voltage and constant current control circuit, a linear regulation control circuit, a voltage and current acquisition circuit, a voltage acquisition processing circuit and a discharge control circuit; the main control circuit is connected to the constant voltage and constant current control circuit, the constant voltage and constant current control circuit is connected to the linear regulation control circuit; the voltage and current acquisition circuit is respectively connected to the constant voltage and constant current control circuit, the main control circuit and the voltage acquisition processing circuit; the discharge control circuit is connected to the voltage acquisition processing circuit; the voltage acquisition processing circuit is connected to the main control circuit; when performing an overcurrent protection test, the test load is respectively connected to the linear regulation control circuit, the voltage and current acquisition circuit and the discharge control circuit. The present invention can effectively solve the problem of output voltage convex wave caused by the instantaneous shutdown of the current due to the disconnection of the output circuit, resulting in the instantaneous loss of control of the entire circuit.

Description

Technical Field

[0001] The present invention relates to the field of lithium battery pack testing, and in particular to a control circuit and a control method for a constant current source output voltage convex wave. Background Art

[0002] During the production process of finished lithium battery packs and their protection boards, the charging overcurrent protection of finished lithium battery packs and their protection boards must be fully tested. As manufacturers control costs, the voltage withstand value fluctuation space of the related devices used in the finished lithium battery packs and their protection boards is controlled very small; when testing the charging overcurrent protection, the current is instantly shut off due to the output circuit disconnection, and the entire circuit will instantly lose control and cause output voltage surges. This voltage surge is required not to exceed the voltage withstand value of the related devices in the finished lithium battery pack and its protection board, otherwise it will damage the related devices.

[0003] In the prior art, there are mainly two methods for processing voltage spurs: the first method is to require the output wiring impedance to be reduced to a certain value, which can be specifically set to a smaller output value by adjusting the front-end voltage of the constant current source. In this way, when the output peripheral circuit of the constant current source is disconnected instantly, the voltage spur caused will be relatively smaller; however, reducing the output wiring impedance is a treatment method that only treats the symptoms but not the root cause. It can only be based on setting the low point of the front-end voltage to minimize the output voltage spur so that it does not exceed the requirements. The second method is to adjust the regulation characteristics and shutdown output index of the feedback circuit, sacrifice the circuit response time characteristics, and try to limit the voltage spur after the charging overcurrent protection; however, adjusting the regulation characteristics of the feedback circuit is to slow down the rise time of the voltage spur at the expense of the response time of the overall feedback circuit. When it is quickly shut down, the overall usability of the circuit will be limited, and it is completely unsuitable for some fields that require rapid protection and shutdown. Therefore, it is urgent to provide a voltage spur processing solution to effectively solve the problem that the current is instantly shut down due to the disconnection of the output circuit, resulting in the instantaneous loss of control of the entire circuit, causing the output voltage spur and damaging related devices. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a control circuit and control method for a constant current source output voltage spur, which is used to effectively solve the problem that the output circuit is disconnected and the current is instantly shut down, resulting in the entire circuit being instantly out of control, causing output voltage spur and damaging related devices.

[0005] The present invention is implemented as follows: a control circuit for a constant current source output voltage convex wave, comprising a main control circuit, a constant voltage and constant current control circuit, a linear regulation control circuit, a voltage and current acquisition circuit, a voltage acquisition processing circuit and a discharge control circuit;

[0006] The main control circuit is connected to the constant voltage and constant current control circuit, and the constant voltage and constant current control circuit is connected to the linear regulation control circuit; the voltage and current acquisition circuit is respectively connected to the constant voltage and constant current control circuit, the main control circuit and the voltage acquisition processing circuit; the discharge control circuit is connected to the voltage acquisition processing circuit; the voltage acquisition processing circuit is connected to the main control circuit;

[0007] When performing an overcurrent protection test, the test load is connected to the linear regulation control circuit, the voltage and current acquisition circuit, and the discharge control circuit respectively;

[0008] During operation, the main control circuit enables the constant voltage and constant current control circuit to output a high level, and the high level enables the linear regulation control circuit to output voltage and current values; the voltage and current acquisition circuit acquires the voltage and current values ​​on the loop in real time; the voltage and current acquisition circuit feeds back the acquired voltage and current values ​​to the constant voltage and constant current control circuit, so that the constant voltage and constant current control circuit can adjust the voltage and current output of the linear regulation control circuit; the voltage and current acquisition circuit provides the acquired voltage and current values ​​to the main control circuit for real-time monitoring and processing; the voltage and current acquisition circuit provides the acquired voltage values ​​to the voltage acquisition processing circuit, so that the voltage acquisition processing circuit can enable the discharge control circuit to perform discharge processing in real time and output the feedback level to the main control circuit for monitoring and processing in real time.

[0009] Furthermore, the constant voltage and constant current control circuit includes a voltage operational amplifier, a current operational amplifier, a first diode and a second diode;

[0010] The positive input terminals of the voltage operational amplifier and the current operational amplifier are both connected to the main control circuit, and the negative input terminals of the voltage operational amplifier and the current operational amplifier are both connected to the voltage and current acquisition circuit; the output terminals of the voltage operational amplifier and the current operational amplifier are both connected to the linear regulation control circuit; the first diode is connected in parallel to the output terminal of the current operational amplifier, and the second diode is connected in parallel to the output terminal of the voltage operational amplifier.

[0011] Furthermore, the linear regulation control circuit includes a first MOS tube and a first resistor;

[0012] The G pole of the first MOS tube is connected to the constant voltage and constant current control circuit, and the D pole of the first MOS tube is connected to the power supply; the S pole of the first MOS tube is connected to the positive voltage sampling end of the voltage and current acquisition circuit; one end of the first resistor is respectively connected to the negative voltage sampling end and the positive current sampling end of the voltage and current acquisition circuit, and the other end of the first resistor is respectively connected to the ground and the negative current sampling end of the voltage and current acquisition circuit.

[0013] Furthermore, the voltage and current acquisition circuit includes a voltage acquisition operational amplifier and a current acquisition operational amplifier;

[0014] The input end of the voltage acquisition amplifier is connected to the two voltage output ends of the linear regulation control circuit, and the output end of the voltage acquisition amplifier is connected to the main control circuit, the voltage acquisition processing circuit and the constant voltage and constant current control circuit respectively;

[0015] The input end of the current collection amplifier is connected to the two current collection ends of the linear regulation control circuit, and the output end of the current collection amplifier is connected to the main control circuit and the constant voltage and constant current control circuit respectively.

[0016] Further, the voltage acquisition and processing circuit includes a fast comparator, a second resistor, a third resistor, a fourth resistor and a fifth resistor;

[0017] The positive input terminal of the fast comparator is connected to the voltage and current acquisition circuit, and the output terminal of the fast comparator is respectively connected to the main control circuit and the discharge control circuit; one end of the second resistor is connected to the main control circuit, one end of the third resistor is connected to the reference power supply, one end of the fourth resistor is grounded, and the other ends of the second resistor, the third resistor and the fourth resistor are all connected to the negative input terminal of the fast comparator; one end of the fifth resistor is connected to the output terminal of the fast comparator, and the other end is connected to the pull-up power supply.

[0018] Further, the discharge control circuit includes a second MOS tube, a capacitor, a sixth resistor and a seventh resistor;

[0019] The G pole of the second MOS tube is connected to the voltage acquisition and processing circuit; the D pole of the second MOS tube is connected to one end of the capacitor, and the sixth resistor is connected in parallel with the capacitor; one end of the seventh resistor is connected to the other end of the capacitor; the S pole of the second MOS tube and the other end of the seventh resistor are both connected to the linear regulation control circuit.

[0020] Furthermore, the main control circuit adopts a TMS320F28377S chip.

[0021] The present invention is implemented as follows: a control method for a constant current source output voltage convex wave, the control method needs to use the above control circuit, the control method includes:

[0022] The main control circuit sets the voltage output value V set And the current output value I set , V set and I set The signal is output to the constant voltage and constant current control circuit; the constant voltage and constant current control circuit receives Vset and I set After the signal is received, the high level is enabled to drive the first MOS tube in the linear regulation control circuit to conduct, thereby outputting the voltage and current value;

[0023] The voltage and current acquisition circuit acquires the voltage VFB and current IFB in the loop; the voltage and current acquisition circuit feeds back the collected voltage VFB and IFB current signals to the constant voltage and constant current control circuit in real time, so that the constant voltage and constant current control circuit can adjust the conduction degree of the first MOS tube in the linear regulation control circuit, so that the linear regulation control circuit can stably output the required voltage and current values; the voltage and current acquisition circuit feeds back the collected voltage VFB and current IFB signals to the main control circuit in real time, so that the main control circuit can perform real-time monitoring and processing; the voltage and current acquisition circuit feeds back the collected voltage VFB signal to the voltage acquisition processing circuit in real time;

[0024] The voltage acquisition and processing circuit compares the received voltage VFB signal with the internally set fixed voltage value in real time, and when the rise change of the compared voltage VFB signal is greater than the set fixed voltage value, the fast comparator of the voltage acquisition and processing circuit is enabled to output a high-level pulse to the discharge control circuit; at the same time, the voltage acquisition and processing circuit feeds back the rise change of the voltage VFB signal to the main control circuit for monitoring and processing;

[0025] After receiving the high level pulse, the discharge control circuit enables the second MOS tube in the discharge control circuit to be turned on, thereby discharging and lowering the output voltage of the linear regulation control circuit.

[0026] The present invention has the following advantages: the present invention uses a voltage acquisition and processing circuit to compare the collected voltage value rise changes in real time, and outputs a high-level pulse when a voltage swell occurs, and enables a discharge control circuit to discharge the output voltage of the linear regulation control circuit through the high-level pulse, thereby instantly lowering the output voltage of the linear regulation control circuit; therefore, the technical solution of the present invention can effectively solve the problem of output voltage swells caused by the output circuit being disconnected and the current being instantly shut down, resulting in the entire circuit being instantly out of control. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0028] Figure 1 The present invention is a circuit principle block diagram of a control circuit for a constant current source output voltage convex wave.

[0029] Figure 2 4 is a circuit structure diagram of the main control circuit in the present invention.

[0030] Figure 3 It is a circuit structure diagram of the constant voltage and constant current control circuit and the linear regulation control circuit in the present invention.

[0031] Figure 4 It is a circuit structure diagram of the voltage and current acquisition circuit in the present invention.

[0032] Figure 5 It is a circuit structure diagram of the voltage acquisition and processing circuit in the present invention.

[0033] Figure 6 It is a circuit structure diagram of the discharge control circuit in the present invention. DETAILED DESCRIPTION

[0034] See also Figures 1 to 6 As shown, a preferred embodiment of a control circuit 100 of a constant current source output voltage convex wave of the present invention, the control circuit 100 includes a main control circuit 1, a constant voltage and constant current control circuit 2, a linear regulation control circuit 3, a voltage and current acquisition circuit 4, a voltage acquisition processing circuit 5 and a discharge control circuit 6;

[0035] The main control circuit 1 is connected to the constant voltage and constant current control circuit 2, and the constant voltage and constant current control circuit 2 is connected to the linear regulation control circuit 3; the voltage and current acquisition circuit 4 is respectively connected to the constant voltage and constant current control circuit 2, the main control circuit 1 and the voltage acquisition processing circuit 5; the discharge control circuit 6 is connected to the voltage acquisition processing circuit 5; the voltage acquisition processing circuit 5 is connected to the main control circuit 1;

[0036] When performing an overcurrent protection test, the test load 200 (i.e., the finished product of the lithium battery pack and its protection board) is connected to the linear regulation control circuit 3, the voltage and current acquisition circuit 4, and the discharge control circuit 6 respectively;

[0037] During operation, the main control circuit 1 enables the constant voltage and constant current control circuit 2 to output a high level, and the high level enables the linear regulation control circuit 3 to output a voltage and current value; the voltage and current acquisition circuit 4 acquires the voltage and current values ​​on the loop in real time; the voltage and current acquisition circuit 4 feeds back the acquired voltage and current values ​​to the constant voltage and constant current control circuit 2, so that the constant voltage and constant current control circuit 2 can adjust the voltage and current output of the linear regulation control circuit 3; the voltage and current acquisition circuit 4 provides the acquired voltage and current values ​​to the main control circuit 1 for real-time monitoring and processing. In specific implementation, the main control circuit 1 will collect, monitor, display and other processing on the received voltage and current values; the voltage and current acquisition circuit 4 provides the acquired voltage value to the voltage acquisition processing circuit 5, so that the voltage acquisition processing circuit 5 can enable the discharge control circuit 6 to perform discharge processing in real time and feedback the level output to the main control circuit 1 in real time for monitoring and processing, and the main control circuit 1 will collect, monitor, display and other processing on the output level. Wherein, the main control circuit is implemented by using TMS320F28377S chip.

[0038] In this embodiment, please refer to Figure 3 As shown, the constant voltage and constant current control circuit 2 includes a voltage operational amplifier N1A, a current operational amplifier N1B, a first diode D1 and a second diode D2;

[0039] The positive input terminals of the voltage amplifier N1A and the current amplifier N1B are connected to the main control circuit 1; the negative input terminals of the voltage amplifier N1A and the current amplifier N1B are connected to the voltage and current acquisition circuit 4; the output terminals of the voltage amplifier N1A and the current amplifier N1B are connected to the linear regulation control circuit 3; the first diode D1 is connected in parallel to the output terminal of the current amplifier N1B, and the second diode D2 is connected in parallel to the output terminal of the voltage amplifier N1A. The voltage amplifier N1A and the current amplifier N1B can be implemented by using the ADA4522-2 amplifier.

[0040] In the constant voltage and constant current control circuit 2, the two input terminals of the voltage amplifier N1A are respectively provided with a resistor R7 and a resistor R11, and the output terminal of the voltage amplifier N1A is provided with a resistor R9; the two input terminals of the current amplifier N1B are respectively provided with a resistor R1 and a resistor R4, and the output terminal of the current amplifier N1B is provided with a resistor R2; wherein the resistors R7, R11, R1 and R4 mainly play a matching role, and the resistors R9 and R2 mainly play a driving role. wherein the first diode D1 mainly plays a role in accelerating the shutdown and protecting the resistor R2, and the second diode D2 mainly plays a role in accelerating the shutdown and protecting the resistor R9.

[0041] When the constant voltage and constant current control circuit 2 is working, when the constant voltage and constant current control circuit 2 receives the V set and output by the main control circuit 1 set and I set When the voltage amplifier N1A and the current amplifier N1B are fed back by the voltage and current acquisition circuit 4, the voltage amplifier N1A and the current amplifier N1B are enabled to output a high level to the linear regulation control circuit 3. When the constant voltage and constant current control circuit 2 receives the voltage VFB and current IFB signals fed back by the voltage and current acquisition circuit 4, the voltage amplifier N1A and the current amplifier N1B are enabled to adjust the output high level.

[0042] In this embodiment, please refer to Figure 3 As shown, the linear regulation control circuit 3 includes a first MOS tube Q1 and a first resistor R6;

[0043] The G pole of the first MOS tube Q1 is connected to the constant voltage and constant current control circuit 2, and the D pole of the first MOS tube Q1 is connected to the power supply VCC; the S pole of the first MOS tube Q1 is connected to the positive voltage sampling end of the voltage and current acquisition circuit 4; one end of the first resistor R6 is respectively connected to the negative voltage sampling end and the positive current sampling end of the voltage and current acquisition circuit 4, and the other end of the first resistor R6 is respectively connected to the ground GND and the negative current sampling end of the voltage and current acquisition circuit 4. The third resistor R6 is mainly used for sampling.

[0044] When the linear regulation control circuit 3 is working, it is necessary to connect the output terminal PV+ / PV- of the linear regulation control circuit 3 to the test load 200, so as to load the voltage output by the linear regulation control circuit 3 onto the test load 200 for testing. When the linear regulation control circuit 3 receives the high level output by the constant voltage and constant current control circuit 2, it will drive the first MOS tube Q1 to conduct, thereby outputting the voltage and current value. At the same time, according to the constant voltage and constant current control circuit 2, the high level output is adjusted to drive the first MOS tube Q1 to adjust the conduction degree, so as to achieve the voltage and current value required for stable output.

[0045] In this embodiment, please refer to Figure 4 As shown, the voltage and current acquisition circuit 4 includes a voltage acquisition operational amplifier N2A and a current acquisition operational amplifier N2B;

[0046] The input end of the voltage acquisition amplifier N2A is connected to the two voltage output ends PV+ / PV- of the linear regulation control circuit 3, and the output end of the voltage acquisition amplifier N2A is respectively connected to the main control circuit 1, the voltage acquisition processing circuit 5 and the constant voltage and constant current control circuit 2;

[0047] The input end of the current acquisition amplifier N2B is connected to the two current acquisition terminals Is+ / Is- of the linear regulation control circuit 3, and the output end of the current acquisition amplifier N2B is respectively connected to the main control circuit 1 and the constant voltage and constant current control circuit 5. Among them, the voltage acquisition amplifier N2A and the current acquisition amplifier N2B can both be implemented by ADA4522-2 amplifier.

[0048] In the voltage and current acquisition circuit 4, a resistor R15 is provided at the negative input terminal of the voltage acquisition amplifier N2A, a resistor R13 and a resistor R12 are provided in parallel at the positive input terminal of the voltage acquisition amplifier N2A, and one end of the resistor R12 is grounded GND; a resistor R23 is provided at the negative input terminal of the current acquisition amplifier N2B, a resistor R20 and a resistor R18 are provided in parallel at the positive input terminal of the voltage acquisition amplifier N2B, and one end of the resistor R18 is grounded GND; the output terminal of the voltage acquisition amplifier N2A A resistor R14 is provided, and a resistor R16 is provided between the output terminal and the negative input terminal of the voltage acquisition amplifier N2A; a resistor R21 is provided at the output terminal of the current acquisition amplifier N2B, and a resistor R26 is provided between the output terminal and the negative input terminal of the current acquisition amplifier N2B; wherein, the resistors R12, R13, R15, R18, R20, and R23 mainly play a matching role, and the resistors R14, R16, R21, and R26 mainly play a driving role.

[0049] When the voltage and current acquisition circuit 4 is working, the voltage output by the linear regulation control circuit 3 can be acquired through the voltage acquisition operational amplifier N2A, and the current of the first resistor R6 in the linear regulation control circuit 3 can be acquired through the current acquisition operational amplifier N2B; the collected voltage VFB and current IFB signals are fed back to the main control circuit 1, the voltage acquisition processing circuit 5 and the constant voltage and constant current control circuit 2 respectively.

[0050] In this embodiment, please refer to Figure 5 As shown, the voltage acquisition and processing circuit 5 includes a fast comparator N3A, a second resistor R27, a third resistor R24, a fourth resistor R25 and a fifth resistor R17;

[0051] The positive input terminal of the fast comparator N3A is connected to the voltage and current acquisition circuit 4, and the output terminal of the fast comparator N3A is respectively connected to the main control circuit 1 and the discharge control circuit 6; one end of the second resistor R27 is connected to the main control circuit 1, one end of the third resistor R24 ​​is connected to the reference power supply VREF, one end of the fourth resistor R25 is grounded GND, and the other ends of the second resistor R27, the third resistor R24 ​​and the fourth resistor R25 are all connected to the negative input terminal of the fast comparator N3A; one end of the fifth resistor R17 is connected to the output terminal of the fast comparator N3A, and the other end is connected to the pull-up power supply VCCD.

[0052] Among them, the fast comparator N3A is mainly used to compare the rise change of the voltage VFB signal fed back by the voltage and current acquisition circuit 4 with the internally set fixed voltage value Vset-FB, and output the corresponding level according to the comparison result. The fast comparator N3A can adopt the SGM8745 comparator; the second resistor R27, the third resistor R24 ​​and the fourth resistor R25 mainly play the role of matching the voltage divider; the fifth resistor R17 plays the role of pulling up the voltage.

[0053] In the voltage acquisition and processing circuit 5, a resistor R19 is provided at the negative input end of the fast comparator N3A, and a resistor R22 is provided at the positive input end of the fast comparator N3A; the resistor R19 and the resistor R22 mainly play a matching role.

[0054] When the voltage acquisition and processing circuit 5 is working, it will compare the rise change of the voltage VFB signal fed back by the voltage and current acquisition circuit 4 with the internally set fixed voltage value Vset-FB in real time, and if the rise change of the voltage VFB signal is greater than the internally set fixed voltage value Vset-FB, it will output a high-level pulse; if the rise change of the voltage VFB signal is less than or equal to the internally set fixed voltage value Vset-FB, it will output a low-level pulse; at the same time, the level pulse will also be output to the main control circuit 1 and the discharge control circuit 6.

[0055] In this embodiment, please refer to Figure 6 As shown, the discharge control circuit 6 includes a second MOS tube Q2, a capacitor C1, a sixth resistor R5 and a seventh resistor R3;

[0056] The G pole of the second MOS tube Q2 is connected to the voltage acquisition and processing circuit 5; the D pole of the second MOS tube Q2 is connected to one end of the capacitor C1, and the sixth resistor R5 is connected in parallel with the capacitor C1; one end of the seventh resistor R3 is connected to the other end of the capacitor C1; the S pole of the second MOS tube Q2 and the other end of the seventh resistor R3 are both connected to the linear regulation control circuit 3.

[0057] In the discharge control circuit 6 , the G pole of the second MOS tube Q2 is also connected to a resistor R8 and a resistor R10 respectively, and one end of the resistor R10 is grounded GND; the resistor R8 and the resistor R10 mainly play a driving role.

[0058] When the discharge control circuit 6 is working, after receiving the high level pulse output by the voltage acquisition and processing circuit 5, the second MOS tube Q2 is enabled to be turned on, thereby discharging and lowering the output voltage of the linear regulation control circuit 3, so as to achieve the purpose of reducing the output voltage convex wave caused by the instantaneous current shutdown due to the disconnection of the output loop, resulting in the instantaneous loss of control of the entire circuit.

[0059] The present invention further provides a method for controlling a constant current source output voltage convex wave, the control method needs to use the above-mentioned control circuit 100, and the control method includes:

[0060] The main control circuit 1 sets the voltage output value V set And the current output value I set , V can be set according to the actual output requirements set and I set , V set and I set The signal is output to the constant voltage and constant current control circuit 2; the constant voltage and constant current control circuit 2 receives V set and I set After the signal is received, the high level is output to drive the first MOS tube Q1 in the linear regulation control circuit 3 to be turned on, thereby outputting the voltage and current value;

[0061] The voltage and current acquisition circuit 4 acquires the voltage VFB and current IFB in the loop; the voltage and current acquisition circuit 4 feeds back the collected voltage VFB and IFB current signals to the constant voltage and constant current control circuit 2 in real time, so that the constant voltage and constant current control circuit 2 can adjust the conduction degree of the first MOS tube Q1 in the linear regulation control circuit 3, so that the linear regulation control circuit 3 can stably output the required voltage and current values; the voltage and current acquisition circuit 4 feeds back the collected voltage VFB and current IFB signals to the main control circuit 1 in real time, so that the main control circuit 1 can perform real-time monitoring and processing (specifically, it can perform collection, monitoring, display and other processing); the voltage and current acquisition circuit 4 feeds back the collected voltage VFB signal to the voltage acquisition processing circuit 5 in real time;

[0062] The voltage acquisition and processing circuit 5 compares the received voltage VFB signal with the internally set fixed voltage value Vset-FB in real time, and when the compared voltage VFB signal rises and changes more than the set fixed voltage value Vset-FB, the fast comparator N3A of the voltage acquisition and processing circuit 5 is enabled to output a high-level pulse to the discharge control circuit 6; at the same time, the voltage acquisition and processing circuit 5 feeds back the rise and change of the voltage VFB signal to the main control circuit 1 for monitoring and processing (specifically, it can be collected, monitored, displayed, etc.); in specific implementation, when the external loop is not disconnected, the rise and change of the voltage VFB signal collected by the voltage and current acquisition circuit 4 will not be greater than the fixed voltage value Vset-FB, so the fast comparator N3A will output a low-level pulse. When the external circuit is disconnected and the current is instantly cut off, the linear regulation control circuit 4 will be out of control, which will cause the output voltage V+ of the linear regulation control circuit 4 to be instantly pulled up, thereby forming a convex wave; at this time, the rise change of the voltage VFB signal collected by the voltage and current acquisition circuit 4 will be greater than the fixed voltage value Vset-FB, so the fast comparator N3A will output a high-level pulse.

[0063] After receiving the high level pulse, the discharge control circuit 6 enables the second MOS tube Q2 in the discharge control circuit 6 to be turned on, thereby discharging and lowering the output voltage V+ of the linear regulation control circuit 3, so as to achieve the purpose of reducing the output voltage spur caused by the instantaneous shutdown of the current due to the disconnection of the output loop, resulting in the instantaneous loss of control of the entire circuit.

[0064] To sum up, the present invention uses a voltage acquisition and processing circuit to compare the collected voltage value rise changes in real time, and outputs a high-level pulse when a voltage swell occurs. The high-level pulse enables the discharge control circuit to discharge the output voltage of the linear regulation control circuit, thereby instantly lowering the output voltage of the linear regulation control circuit. Therefore, the technical solution of the present invention can effectively solve the problem of output voltage swells caused by the output circuit being disconnected and the current being instantly shut down, resulting in the entire circuit being instantly out of control.

[0065] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A control circuit for a constant current source output voltage convex wave, characterized in that: It includes a main control circuit, a constant voltage and constant current control circuit, a linear regulation control circuit, a voltage and current acquisition circuit, a voltage acquisition processing circuit and a discharge control circuit; The main control circuit is connected to the constant voltage and constant current control circuit, and the constant voltage and constant current control circuit is connected to the linear regulation control circuit; the voltage and current acquisition circuit is respectively connected to the constant voltage and constant current control circuit, the main control circuit and the voltage acquisition processing circuit; the discharge control circuit is connected to the voltage acquisition processing circuit; the voltage acquisition processing circuit is connected to the main control circuit; The constant voltage and constant current control circuit comprises a voltage operational amplifier, a current operational amplifier, a first diode and a second diode; The positive input terminals of the voltage operational amplifier and the current operational amplifier are both connected to the main control circuit, and the negative input terminals of the voltage operational amplifier and the current operational amplifier are both connected to the voltage and current acquisition circuit; the output terminals of the voltage operational amplifier and the current operational amplifier are both connected to the linear regulation control circuit; the first diode is connected in parallel to the output terminal of the current operational amplifier, and the second diode is connected in parallel to the output terminal of the voltage operational amplifier; The linear regulation control circuit includes a first MOS tube and a first resistor; The G pole of the first MOS tube is connected to the constant voltage and constant current control circuit, and the D pole of the first MOS tube is connected to the power supply; the S pole of the first MOS tube is connected to the positive voltage sampling terminal of the voltage and current acquisition circuit; one end of the first resistor is respectively connected to the negative voltage sampling terminal and the positive current sampling terminal of the voltage and current acquisition circuit, and the other end of the first resistor is respectively connected to the ground and the negative current sampling terminal of the voltage and current acquisition circuit; The discharge control circuit includes a second MOS tube, a capacitor, a sixth resistor and a seventh resistor; The G pole of the second MOS tube is connected to the voltage acquisition and processing circuit; the D pole of the second MOS tube is connected to one end of the capacitor, and the sixth resistor is connected in parallel with the capacitor; one end of the seventh resistor is connected to the other end of the capacitor; the S pole of the second MOS tube and the other end of the seventh resistor are both connected to the linear regulation control circuit; When performing an overcurrent protection test, the test load is connected to the linear regulation control circuit, the voltage and current acquisition circuit, and the discharge control circuit respectively; When working, the main control circuit is enabled to trigger the constant voltage and constant current control circuit to output a high level, and the high level is enabled to drive the linear regulation control circuit to output voltage and current values; the voltage and current acquisition circuit acquires the voltage and current values ​​on the loop in real time; the voltage and current acquisition circuit feeds the acquired voltage and current values ​​back to the constant voltage and constant current control circuit, so that the constant voltage and constant current control circuit can adjust the voltage and current output of the linear regulation control circuit; The voltage and current acquisition circuit provides the acquired voltage and current values ​​to the main control circuit for real-time monitoring and processing; The voltage and current acquisition circuit provides the acquired voltage value to the voltage acquisition processing circuit, so that the voltage acquisition processing circuit can enable the discharge control circuit to perform discharge processing in real time and output the real-time feedback level to the main control circuit for monitoring processing.

2. A control circuit for outputting a voltage convex wave of a constant current source according to claim 1, characterized in that: The voltage and current acquisition circuit includes a voltage acquisition operational amplifier and a current acquisition operational amplifier; The input end of the voltage acquisition amplifier is connected to the two voltage output ends of the linear regulation control circuit, and the output end of the voltage acquisition amplifier is connected to the main control circuit, the voltage acquisition processing circuit and the constant voltage and constant current control circuit respectively; The input end of the current collection amplifier is connected to the two current collection ends of the linear regulation control circuit, and the output end of the current collection amplifier is connected to the main control circuit and the constant voltage and constant current control circuit respectively.

3. A control circuit for outputting a voltage convex wave of a constant current source according to claim 1, characterized in that: The voltage acquisition and processing circuit includes a fast comparator, a second resistor, a third resistor, a fourth resistor and a fifth resistor; The positive input terminal of the fast comparator is connected to the voltage and current acquisition circuit, and the output terminal of the fast comparator is respectively connected to the main control circuit and the discharge control circuit; one end of the second resistor is connected to the main control circuit, one end of the third resistor is connected to the reference power supply, one end of the fourth resistor is grounded, and the other ends of the second resistor, the third resistor and the fourth resistor are all connected to the negative input terminal of the fast comparator; one end of the fifth resistor is connected to the output terminal of the fast comparator, and the other end is connected to the pull-up power supply.

4. A control circuit for outputting a voltage convex wave of a constant current source according to claim 1, characterized in that: The main control circuit adopts TMS320F28377S chip.

5. A method for controlling a convex wave of a constant current source output voltage, characterized in that: The control method needs to use the control circuit as described in any one of claims 1 to 4, and the control method includes: The main control circuit sets the voltage output value V set And the current output value I set , V set and I set The signal is output to the constant voltage and constant current control circuit; the constant voltage and constant current control circuit receives V set and I set After the signal is received, the high level is enabled to drive the first MOS tube in the linear regulation control circuit to conduct, thereby outputting the voltage and current value; The voltage and current acquisition circuit acquires the voltage VFB and current IFB in the loop; the voltage and current acquisition circuit feeds back the collected voltage VFB and IFB current signals to the constant voltage and constant current control circuit in real time, so that the constant voltage and constant current control circuit can adjust the conduction degree of the first MOS tube in the linear regulation control circuit, so that the linear regulation control circuit can stably output the required voltage and current values; the voltage and current acquisition circuit feeds back the collected voltage VFB and current IFB signals to the main control circuit in real time, so that the main control circuit can perform real-time monitoring and processing; the voltage and current acquisition circuit feeds back the collected voltage VFB signal to the voltage acquisition processing circuit in real time; The voltage acquisition and processing circuit compares the received voltage VFB signal with the internally set fixed voltage value in real time, and when the rise change of the compared voltage VFB signal is greater than the set fixed voltage value, the fast comparator of the voltage acquisition and processing circuit is enabled to output a high-level pulse to the discharge control circuit; at the same time, the voltage acquisition and processing circuit feeds back the rise change of the voltage VFB signal to the main control circuit for monitoring and processing; After receiving the high level pulse, the discharge control circuit enables the second MOS tube in the discharge control circuit to be turned on, thereby discharging and lowering the output voltage of the linear regulation control circuit.

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