A high-precision bipolar linear high-voltage regulating circuit

Abstract

The application discloses a high-precision bipolar linear high-voltage regulating circuit and belongs to the technical field of linear regulating circuits. The high-precision bipolar linear high-voltage regulating circuit comprises an operational amplifier U1, triodes Q1-Q4, a negative high-voltage end -HV, a positive high-voltage end +HV, an input control voltage end VSET and an output end VOUT. The positive input end of the operational amplifier U1 is connected with the input control voltage end VSET in series with a resistor R1, the negative input end is grounded in series with a resistor R2, the output end and the negative input end are connected with a capacitor C1 in parallel, the output end is connected with the emitter of the triode Q3, the base of the triode Q3 is grounded, the collector of the triode Q3 is connected with the base of the triode Q4, the emitter of the triode Q4 is directly connected with the negative high-voltage end -HV, the collector of the triode Q4 is connected with one end of a resistor R5 and the emitter of the triode Q2, and the other end of the resistor R5 is connected with one end of a resistor R6. The high-precision bipolar linear high-voltage regulating circuit realizes a bipolar, adjustable, high-precision and high-voltage output linear circuit at low cost.

Description

Technical Field

[0001] This invention relates to the field of linear voltage regulation circuit technology, specifically to a high-precision bipolar linear high-voltage regulation circuit. Background Technology

[0002] For low-voltage output voltage regulation circuits, operational amplifiers can be used. However, for adjustable high-voltage outputs of tens or hundreds of volts, only ready-made adjustable high-voltage modules or high-voltage operational amplifiers can be selected. Adjustable high-voltage modules are expensive to purchase, have limited output voltage range options, and even fewer modules with bipolar outputs, making it impossible to achieve flexible output voltage configuration. High-voltage operational amplifiers are limited by the size of the chip's insulation characteristics, which restricts the maximum power supply voltage, generally to within 200V. Moreover, they are expensive and have long procurement cycles.

[0003] The aforementioned problems urgently need to be solved. Therefore, a high-precision bipolar linear high-voltage regulation circuit is proposed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: how to solve the technical problems mentioned in the background art above, and to provide a high-precision bipolar linear high-voltage regulation circuit.

[0005] This invention solves the above-mentioned technical problems through the following technical solution: The invention includes an operational amplifier U1, transistors Q1 to Q4, a negative high-voltage terminal -HV, a positive high-voltage terminal +HV, an input control voltage terminal VSET, and an output terminal VOUT; the positive input terminal of the operational amplifier U1 is connected to the input control voltage terminal VSET via a series resistor R1, the negative input terminal is grounded via a series resistor R2, and a capacitor C1 is connected in parallel between the output terminal and the negative input terminal. The output terminal is also connected to the emitter of transistor Q3, the base of transistor Q3 is grounded, and the collector of transistor Q3 is connected to the base of transistor Q4. The emitter of transistor Q4 is directly connected to the negative high-voltage terminal -HV. The collector is connected to one end of resistor R5 and also to the emitter of transistor Q2. The other end of resistor R5 is connected to one end of resistor R6. The other end of resistor R6 is connected to the base of transistor Q2 and also to the emitter of transistor Q1. The collector of transistor Q2 is connected to one end of resistor R7 and also to the base of transistor Q1. The collector of Q1 is connected to the positive high-voltage terminal +HV. The other end of resistor R7 is also connected to the positive high-voltage terminal +HV. The output terminal VOUT is led out from the port where resistors R5 and R6 are interconnected.

[0006] The output terminal VOUT is directly fed back to the input terminal as the feedback voltage through resistor R8. One end of resistor R8 is connected to the output terminal VOUT, and the other end of resistor R8 is connected to the positive input terminal of operational amplifier U1.

[0007] Furthermore, the high-precision bipolar linear high-voltage regulation circuit also includes a resistor R3 for current limiting, and the output terminal of the operational amplifier U1 is connected in series with the resistor R3 and the emitter of the transistor Q3.

[0008] Furthermore, the high-precision bipolar linear high-voltage regulation circuit also includes a resistor R4 for providing bias current. One end of the resistor R4 is connected to the collector of transistor Q3 and the base of transistor Q4, and the other end is grounded.

[0009] Furthermore, the high-precision bipolar linear high-voltage regulation circuit also includes a capacitor C2 for improving the stability of negative feedback, wherein the capacitor C2 is connected in parallel across the resistor R8.

[0010] Furthermore, transistor Q1 operates in the amplification region. By adjusting the conduction level of transistor Q1, the positive high voltage output amplitude of the output terminal VOUT can be adjusted. Transistor Q4 also operates in the amplification region. By adjusting the conduction level of transistor Q4, the negative high voltage output amplitude of the output terminal VOUT can be adjusted.

[0011] Furthermore, the resistor R7 provides base current for transistor Q1. The current flowing through resistor R7 is divided into two paths: one path supplies the base of transistor Q1, and the other path serves as the Ice current for transistor Q2. The magnitude of the Ice current is determined by the collector voltage of Q4. By adjusting the magnitude of the Ice current, the base current of transistor Q1 can be adjusted, thereby adjusting the Vce voltage of transistor Q1.

[0012] Furthermore, when the voltage at the collector of transistor Q4 connected to resistor R5 decreases, the base current of transistor Q2 increases, causing the Ice current of transistor Q2 to increase. At this time, the base current Ib of transistor Q1 decreases, and the on-state voltage drop Vce of transistor Q1 increases, which together reduce the output voltage at the output terminal VOUT. Resistors R5 and R6 are output current-limiting resistors, which limit the magnitude of the output current and also limit the on-state current of transistors Q1 and Q4 in this circuit, thereby realizing voltage feedback regulation at the output terminal VOUT.

[0013] Furthermore, when the output voltage VOUT increases, the voltage at the positive input terminal of operational amplifier U1 increases, and the output voltage of operational amplifier U1 increases, which increases the base current of transistor Q3, reduces the Vce forward voltage drop of transistor Q3, increases the base current of transistor Q4, reduces the Vce forward voltage drop of transistor Q4, reduces the voltage at the connection between resistor R5 and transistor Q4, and reduces the voltage at the output terminal VOUT of the other end of resistor R5, forming negative feedback and ensuring the stability of the output voltage.

[0014] Furthermore, both resistors R1 and R8 are precision resistors, and the output voltage at the output terminal VOUT is determined by both resistors R1 and R8. The output voltage is as follows:

[0015]

[0016] The output terminal VOUT has the opposite voltage polarity to the input control voltage terminal VSET.

[0017] Compared with the prior art, the present invention has the following advantages: the high-precision bipolar linear high-voltage regulation circuit realizes a bipolar, adjustable, high-precision, high-voltage output linear circuit in a low-cost manner. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the high-precision bipolar linear high-voltage regulation circuit in an embodiment of the present invention. Detailed Implementation

[0019] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0020] Example 1

[0021] This embodiment provides a technical solution: a high-precision bipolar linear high-voltage regulation circuit, which is equipped with two bipolar power supplies +HV and -HV, and a variable low-voltage control signal VSET, so as to obtain an output voltage VOUT between -HV and +HV by changing the voltage of VSET.

[0022] VSET can be generated by a DAC to achieve digitally adjustable high-voltage power supply output, or it can be generated by a potentiometer to generate a low-voltage control signal to achieve manually adjustable high-voltage power supply output. The voltage ranges of the two bipolar power supplies, +HV and -HV, can be arbitrarily adjusted, allowing the polarity of the output voltage to change arbitrarily, achieving bipolar or unipolar voltage output. That is, +HV can be designed to be a voltage of 0V or below, and -HV can be a negative voltage less than +HV, achieving free adjustment of the voltage from -HV to +HV (<0V); or -HV can be designed to be a voltage of 0V or above, and +HV can be a positive voltage greater than -HV, achieving free adjustment of the voltage from -HV (≥0V) to +HV.

[0023] An operational amplifier U1 is used to implement the function of an error amplifier. A resistor R1 is connected in series with the input control voltage VSET at its positive input terminal, serving as the positive input resistor. A resistor R2 is connected in series with the negative input terminal and grounded to reduce bias error caused by the input bias current. A capacitor C1 is connected in parallel with the output and negative input terminals of operational amplifier U1 to stabilize its state in linear operation. The output terminal of operational amplifier U1 is connected to resistor R3, the other end of which is connected to the emitter of transistor Q3. Transistor Q3 is a PNP transistor. The base of transistor Q3 is grounded, and the collector of transistor Q3 is connected to the base of transistor Q4. R3 is a current-limiting resistor. The base current of Q3 is adjusted by the output voltage of operational amplifier U1, so that transistor Q3 operates in the amplification region. The on-state voltage drop Vce of transistor Q3 is adjusted to control the linear conduction of transistor Q4. Since operational amplifier U1 is driven by a low-voltage power supply, the withstand voltage of transistor Q3 is selected according to the magnitude of the negative high voltage -HV. It is required that the withstand voltage Vce of transistor Q3 is at least greater than the sum of the absolute value of negative high voltage -HV and the supply voltage of operational amplifier U1.

[0024] Resistor R4 is a pull-down resistor, providing a bias current to ensure the voltage stability of the base of transistor Q4. The emitter of transistor Q4 is directly connected to the negative high voltage -HV. The collector of transistor Q4 is connected to one end of resistor R5, and also to the emitter of transistor Q2. The other end of resistor R5 is connected to one end of resistor R6, and the other end of resistor R6 is connected to the base of transistor Q2, and also to the emitter of transistor Q1. The collector of transistor Q2 is connected to one end of resistor R7, and also to the base of transistor Q1. The collector of transistor Q1 is connected to the positive high voltage +HV, and the other end of resistor R7 is also connected to the positive high voltage +HV. The output voltage VOUT is drawn from the port where resistors R5 and R6 are interconnected.

[0025] The output voltage VOUT is directly fed back to the input terminal through resistor R8 as the feedback voltage. One end of resistor R8 is connected to the output voltage VOUT, and the other end of resistor R8 is connected to the positive input terminal of operational amplifier U1. Capacitor C2 is connected in parallel across resistor R8 to improve the stability of the entire negative feedback.

[0026] Example 2

[0027] An operational amplifier U1 is used to implement the function of an error amplifier. A resistor R1 is connected in series with the input control voltage VSET at its positive input terminal, serving as the positive input resistor. A resistor R2 is connected in series with the negative input terminal and grounded to reduce bias error caused by the input bias current. A capacitor C1 is connected in parallel with the output and negative input terminals of operational amplifier U1 to stabilize its state in linear operation. The output terminal of operational amplifier U1 is connected to resistor R3, the other end of which is connected to the emitter of transistor Q3. Transistor Q3 is a PNP transistor. The base of transistor Q3 is grounded, and the collector of transistor Q3 is connected to the base of transistor Q4. Resistor R3 is a current-limiting resistor. The base current of transistor Q3 is adjusted by the output voltage of operational amplifier U1, so that transistor Q3 operates in the amplification region. The on-state voltage drop of transistor Q3 Vce is adjusted to control the linear conduction of transistor Q4. Since operational amplifier U1 is driven by a low-voltage power supply, the withstand voltage of transistor Q3 is selected according to the magnitude of the negative high voltage -HV. It is required that the withstand voltage of transistor Q3 Vce is at least greater than the sum of the absolute value of negative high voltage -HV and the supply voltage of operational amplifier U1.

[0028] Resistor R4 is a pull-down resistor, providing a bias current to ensure the voltage stability of the base of transistor Q4. The emitter of transistor Q4 is directly connected to the negative high voltage -HV. The collector of transistor Q4 is connected to one end of resistor R5 and also to the emitter of transistor Q2. The other end of resistor R5 is connected to one end of resistor R6, and the other end of resistor R6 is connected to the base of transistor Q2 and also to the emitter of transistor Q1. The collector of transistor Q2 is connected to one end of resistor R7 and also to the base of transistor Q1. The collector of Q1 is connected to the positive high voltage +HV, and the other end of resistor R7 is also connected to the positive high voltage +HV. The output voltage VOUT is drawn from the port where resistors R5 and R6 are interconnected.

[0029] Both transistors Q1 and Q4 need to have their withstand voltage values ​​selected based on the magnitude of the positive high voltage +HV and negative high voltage -HV to ensure that transistors Q1 and Q4 will not be broken down by high voltage within the normal operating voltage range of positive high voltage +HV and negative high voltage -HV.

[0030] Transistor Q1 operates in the amplification region. By adjusting the conduction level of transistor Q1, the positive high voltage output amplitude of the output voltage VOUT can be adjusted. Transistor Q4 also operates in the amplification region. By adjusting the conduction level of transistor Q4, the negative high voltage output amplitude of the output voltage VOUT can be adjusted.

[0031] Resistor R7 provides a base current for transistor Q1. The current flowing through resistor R7 is divided into two paths: one path supplies the base of transistor Q1, and the other path serves as the Ice current for transistor Q2. The magnitude of the Ice current is determined by the collector voltage of Q4. By adjusting the magnitude of Ice, the base current of transistor Q1 can be adjusted, thereby adjusting the Vce voltage of transistor Q1. This allows for flexible adjustment of the positive high voltage bridge arm voltage of the output voltage VOUT.

[0032] When the voltage at the collector connection of resistor R5 and transistor Q4 decreases, the base current of transistor Q2 increases, causing the Ice current of transistor Q2 to increase. At the same time, the base current Ib of transistor Q1 decreases, and the on-state voltage drop Vce of transistor Q1 increases, which together reduces the output voltage VOUT. Resistors R5 and R6 are the output current limiting resistors of this circuit, limiting the magnitude of the output current and also limiting the on-state current of transistors Q1 and Q4 in this circuit, thus achieving normal feedback regulation of the output voltage VOUT.

[0033] The output voltage VOUT is directly fed back to the input terminal through resistor R8 as the feedback voltage. One end of resistor R8 is connected to the output voltage VOUT, and the other end of resistor R8 is connected to the positive input terminal of operational amplifier U1. Capacitor C2 is connected in parallel across resistor R8 to improve the stability of the entire negative feedback.

[0034] Under stable loop conditions, when the output voltage VOUT increases, the voltage at the positive input terminal of operational amplifier U1 increases, and the output voltage of operational amplifier U1 increases, which increases the base current of transistor Q3, reduces the Vce forward voltage drop of transistor Q3, increases the base current of transistor Q4, reduces the Vce forward voltage drop of transistor Q4, and reduces the voltage at the connection between resistor R5 and transistor Q4, forcing the output voltage VOUT at the other end of resistor R5 to decrease, forming a negative feedback to ensure the stability of the output voltage;

[0035] Resistors R1 and R8 are precision resistors to ensure high accuracy and stability of the output voltage. The magnitude of the output voltage VOUT is determined by both resistors R1 and R8, and its magnitude is...

[0036]

[0037] Because the entire circuit is a negative feedback circuit, the output voltage VOUT has the opposite polarity to the input control voltage VSET.

[0038] In summary, the high-precision bipolar linear high-voltage regulation circuit of the above embodiments achieves a bipolar, adjustable, high-precision, high-voltage output linear circuit in a low-cost manner.

[0039] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A high-precision bipolar linear high-voltage regulating circuit, characterized by, The high-precision bipolar linear high-voltage regulating circuit comprises an operational amplifier U1, transistors Q1-Q4, a negative high-voltage terminal -HV, a positive high-voltage terminal +HV, an input control voltage terminal VSET, and an output terminal VOUT; the positive input terminal of the operational amplifier U1 is connected with the input control voltage terminal VSET in series with a resistor R1, the negative input terminal is grounded in series with a resistor R2, the output terminal is connected with the negative input terminal through a capacitor C1, and the output terminal is also connected with the emitter of the transistor Q3; the base of the transistor Q3 is grounded, the collector of the transistor Q3 is connected with the base of the transistor Q4, the emitter of the transistor Q4 is directly connected with the negative high-voltage terminal -HV, the collector of the transistor Q4 is connected with one end of a resistor R5 and also connected with the emitter of the transistor Q2, the other end of the resistor R5 is connected with one end of a resistor R6, the other end of the resistor R6 is connected with the base of the transistor Q2 and also connected with the emitter of the transistor Q1, the collector of the transistor Q2 is connected with one end of a resistor R7 and also connected with the base of the transistor Q1, the collector of the transistor Q1 is connected with the positive high-voltage terminal +HV, and the other end of the resistor R7 is also connected with the positive high-voltage terminal +HV; the output terminal VOUT is led out from the port where the resistor R5 and the resistor R6 are interconnected; The output terminal VOUT is directly used as a feedback voltage and fed back to the input terminal through a resistor R8, one end of the resistor R8 is connected with the output terminal VOUT, and the other end of the resistor R8 is connected with the positive input terminal of the operational amplifier U1. The high-precision bipolar linear high-voltage regulating circuit further comprises a resistor R3 for current limiting, and the output terminal of the operational amplifier U1 is connected with the emitter of the transistor Q3 in series with the resistor R3.

2. A high-precision dual-pole linear high-voltage regulating circuit according to claim 1, characterized in that: The high-precision bipolar linear high-voltage regulating circuit further comprises a resistor R4 for providing a bias current, one end of the resistor R4 is connected with the collector of the transistor Q3 and the base of the transistor Q4, and the other end of the resistor R4 is grounded.

3. A high-precision dual-rail linear high-voltage regulating circuit according to claim 2, characterized in that: The high-precision bipolar linear high-voltage regulating circuit further comprises a capacitor C2 for improving the stability of negative feedback, and the capacitor C2 is connected in parallel across the resistor R8.

4. A high-precision dual-pole linear high-voltage regulating circuit according to claim 3, characterized in that: The transistor Q1 works in an amplification zone, and the positive high-voltage output amplitude of the output terminal VOUT can be adjusted by adjusting the conduction degree of the transistor Q1; the transistor Q4 also works in the amplification zone, and the negative high-voltage output amplitude of the output terminal VOUT can be adjusted by adjusting the conduction degree of the transistor Q4.

5. A high-precision dual-rail linear high-voltage regulating circuit according to claim 4, characterized in that: The resistor R7 provides a base current for the transistor Q1, and the current flowing through the resistor R7 is divided into two paths, one path supplies the base of the transistor Q1, and the other path serves as an Ice current of the transistor Q2; the size of the Ice current is determined by the collector voltage of the transistor Q4, and the base current of the transistor Q1 is adjusted by adjusting the size of the Ice current, thereby realizing the adjustment of the Vce voltage of the transistor Q1.

6. A high-precision dual-rail linear high-voltage regulating circuit according to claim 5, characterized in that: ​ 7. A high-precision dual-rail linear high-voltage regulating circuit according to claim 6, characterized in that: When the voltage drop at the connection of the collector of the transistor Q4 and the resistor R5 decreases, the base current of the transistor Q2 increases, which makes the Ice current of the transistor Q2 increase, at this time, the base current Ib of the transistor Q1 decreases, and the Vce on voltage drop of the transistor Q1 increases, which jointly makes the output voltage of the output terminal VOUT decrease; the resistors R5 and R6 are output current limiting resistors, which limit the size of the output current, and also limit the on current of the transistors Q1 and Q4 in the circuit, realizing the voltage feedback regulation of the output terminal VOUT.

8. A high precision dual rail linear high voltage regulating circuit as claimed in claim 7, characterized in that: When the output voltage of the output terminal VOUT becomes high, the voltage at the positive input terminal of the operational amplifier U1 becomes high, the output voltage of the operational amplifier U1 becomes high, which makes the base current of the transistor Q3 become large, the Vce on voltage drop of the transistor Q3 decreases, the base current of the transistor Q4 increases, the Vce on voltage drop of the transistor Q4 decreases, the voltage drop at the connection of the resistor R5 and the transistor Q4 decreases, the voltage at the other end of the resistor R5, i.e. the output terminal VOUT, becomes low, forming a negative feedback, which ensures the stability of the output voltage.

9. A high precision dual rail linear high voltage regulating circuit as claimed in claim 8, characterized in that: The resistors R1 and R8 are precision resistors, and the size of the output voltage of the output terminal VOUT is determined by the resistors R1 and R8, and the size of the output voltage is: ； Wherein the output terminal VOUT is opposite in voltage polarity to the input control voltage terminal .

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