Safety working area protection circuit suitable for voltage stabilizing integrated circuit

By using P-channel junction field effect transistors in the safe working area protection circuit of the voltage-regulating integrated circuit to provide bias to the transistor and integrating the functions of the overcurrent and overvoltage protection circuit, the problem of the stability of the voltage-regulating integrated circuit is affected, achieving higher stability and integration.

CN222775972UActive Publication Date: 2025-04-18CHINA ZHENHUA GRP YONGGUANG ELECTRONICS CO LTD STATE OWNED NO 873 FACTORY
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Patent Information

Application Number
CN202421450062.8
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-06-24
Publication Date
2025-04-18
Estimated Expiration
2034-06-24

AI Technical Summary

Technical Problem

The existing safety working protection circuit modules of voltage-regulating integrated circuits use transistors as the switching base of bias transistors, and are susceptible to fluctuations in complex circuit environments, affecting their working stability.

Method used

A safe working area protection circuit including an overcurrent protection circuit, a Darlington composite tube, a current-voltage sampling circuit and an overvoltage protection circuit is designed. The P-channel junction field effect transistors Q5 provide bias to transistors Q3 and Q4, improve their stability, and integrate the functions of the overcurrent and overvoltage protection circuit.

Benefits of technology

The stability of transistors Q3 and Q4 is improved, and the problem of the switch base being disturbed by fluctuations in complex circuit environments is solved, making the circuit of the safe working area more stable, while saving chip area and improving integration.

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Abstract

The utility model provides a safe working area protection circuit suitable for a voltage stabilizing integrated circuit. The safe working area protection circuit comprises an overcurrent protection circuit, a Darlington composite tube, a current and voltage sampling circuit and an overvoltage protection circuit which are connected in sequence. The overcurrent protection circuit is also connected with the current and voltage sampling circuit and the overvoltage protection circuit; the positive end of the Darlington composite tube is connected with an input voltage VIN end, and the negative end of the Darlington composite tube is connected with a reference power supply VOUT2 end; the positive end of the overcurrent protection circuit is connected with an input current I3 end, and the negative end of the overcurrent protection circuit is connected with a reference power supply VOUT2 end; the negative end of the current and voltage sampling circuit is connected with the VOUT end of the reference power supply; according to the utility model, the functions of the overvoltage protection circuit and the overcurrent protection circuit are integrated, and a restriction relationship is formed, so that the overvoltage and overcurrent protection functions are realized, and a safe working area or safe power can be limited; and the circuit is simple in structure, the chip area is saved, and the integration level is improved.
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Description

Technical Field

[0001] The utility model belongs to the field of semiconductor integrated circuits, and in particular relates to a safe working area protection circuit suitable for voltage-stabilizing integrated circuits. Background Art

[0002] At present, the existing safety operation protection circuit modules suitable for voltage-stabilizing integrated circuits mostly use transistors as the switch base of the bias transistor. However, such safety operation protection circuit modules make the switch base of the bias transistor susceptible to fluctuations in a complex circuit environment, seriously affecting the working stability of the safety operation protection circuit. Utility Model Content

[0003] In order to solve the above technical problems, the utility model provides a safe operating area protection circuit suitable for a voltage stabilizing integrated circuit.

[0004] The utility model is realized through the following technical solutions.

[0005] The utility model provides a safe working area protection circuit suitable for a voltage-stabilizing integrated circuit, comprising an overcurrent protection circuit, a Darlington compound tube, a current and voltage sampling circuit and an overvoltage protection circuit connected in sequence; the overcurrent protection circuit is also connected to the current and voltage sampling circuit and the overvoltage protection circuit; the positive end of the Darlington compound tube is connected to the input voltage VIN end, and the negative end is connected to the reference power supply VOUT2 end; the positive end of the overcurrent protection circuit is connected to the input current I3 end, and the negative end is connected to the reference power supply VOUT2 end; the negative end of the current and voltage sampling circuit is connected to the reference power supply VOUT end.

[0006] The overcurrent protection circuit includes a transistor Q1, a transistor Q2, a transistor Q3, a transistor Q4, a P-channel junction field effect transistor Q5, a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a capacitor C1;

[0007] The emitter of the transistor Q1, the resistor R1 and one end of the resistor R4 are all connected to the input current I3 end; the base of the transistor Q1 is connected to the other end of the resistor R1, one end of the capacitor C1 and the collector of the transistor Q2, and the collector is connected to the emitter of the transistor Q2 and the reference power supply VOUT2 end; the base of the transistor Q2 is connected to the other end of the capacitor C1 and one end of the resistor R2, and the other end of the resistor R2 is connected to one end of the resistor R3, the gate of the P-channel junction field effect transistor Q5, and the collectors of the transistor Q3 and the transistor Q4; the drain of the P-channel junction field effect transistor Q5 is connected to the base of the transistor Q3 and the transistor Q4, and the source is connected to the other end of the resistor R3 and the resistor R4.

[0008] The Darlington compound tube includes a transistor Q6, a transistor Q7, a transistor Q8, a transistor Q9, a resistor R5, a resistor R6, a resistor R7, and a resistor R8;

[0009] One end of the resistor R5, the emitter of the transistor Q7, and the collectors of the transistors Q8 and Q9 are all connected to the input voltage VIN end, the other end of the resistor R5 is connected to the collector of the transistor Q6 and the base of the transistor Q7, the collector of the transistor Q7 is connected to one end of the resistor R6, the bases of the transistors Q8 and Q9, and the emitters of the transistors Q8 and Q9 are connected to one end of the resistor R7 and the resistor R8, respectively; the base of the transistor Q6 is connected to the input current I3 end, and the emitter is connected to the other end of the resistor R6 and then connected to the reference power supply VOUT2 end.

[0010] The current and voltage sampling circuit includes a resistor R10, a resistor R11, and a resistor R12;

[0011] One end of the resistor R10 is connected to the emitter of the transistor Q4, and the other end is connected to one end of the resistor R11 and the emitter of the transistor Q3; the other end of the resistor R11 is connected to one end of the resistor R12 and the other end of the resistor R8; the other end of the resistor R12 is connected to the other end of the resistor R7 and the reference power supply VOUT.

[0012] The overvoltage protection circuit includes a voltage stabilizing diode Z1, a voltage stabilizing diode Z2, and a resistor R9;

[0013] The cathode of the voltage zener diode Z1 is connected to the input voltage VIN terminal, the anode is connected to the cathode of the voltage zener diode Z2 through the resistor R9, and the anode of the voltage zener diode Z2 is connected to one end of the resistor R10 and the emitter of the crystal terminal Q4.

[0014] The capacitor C1 is a Miller capacitor.

[0015] The P-channel junction field effect transistor Q5 is used to provide bias for the transistor Q3 and the transistor Q4, so as to achieve the stabilization function of the base current of the transistor Q3 and the transistor Q4.

[0016] The beneficial effects of the utility model are: 1) in the overcurrent protection circuit, when the P-channel junction field effect transistor Q5 is used as a large resistor, it is used to provide bias for the transistor Q3 and the transistor Q4, which greatly improves the stability of the transistor Q3 and the transistor Q4, solves the problem that the switch base of the transistor Q3 and the transistor Q4 is disturbed by the fluctuation of the complex circuit environment, and makes the safe working area circuit more stable;

[0017] 2) The overcurrent protection circuit and the overvoltage protection circuit are combined into one as a safe working area protection circuit, and they no longer function separately;

[0018] 3) The overvoltage protection circuit and the overcurrent protection circuit are functionally integrated and form a constraint relationship. They have both the overvoltage and overcurrent protection functions and can limit the safe working area or the safe power. The circuit structure of this utility model not only saves chip area, but also improves integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structural principle of the utility model;

[0020] Figure 2 It is a circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0021] The technical solution of the utility model is further described below, but the scope of protection required is not limited to the description.

[0022] like Figure 1 The schematic diagram of the structure principle of the utility model is shown; a safe working area protection circuit suitable for a voltage-stabilizing integrated circuit, comprising an overcurrent protection circuit, a Darlington compound tube, a current and voltage sampling circuit and an overvoltage protection circuit connected in sequence; the overcurrent protection circuit is also connected to the current and voltage sampling circuit and the overvoltage protection circuit; the positive end of the Darlington compound tube is connected to the input voltage VIN end, and the negative end is connected to the reference power supply VOUT2 end; the positive end of the overcurrent protection circuit is connected to the input current I3 end, and the negative end is connected to the reference power supply VOUT2 end; the negative end of the current and voltage sampling circuit is connected to the reference power supply VOUT end.

[0023] like Figure 2 The figure shows the circuit principle diagram of the utility model; the overcurrent protection circuit includes a transistor Q1, a transistor Q2, a transistor Q3, a transistor Q4, a P-channel junction field effect transistor Q5, a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a capacitor C1;

[0024] The emitter of the transistor Q1, the resistor R1 and one end of the resistor R4 are all connected to the input current I3 end; the base of the transistor Q1 is connected to the other end of the resistor R1, one end of the capacitor C1 and the collector of the transistor Q2, and the collector is connected to the emitter of the transistor Q2 and the reference power supply VOUT2 end; the base of the transistor Q2 is connected to the other end of the capacitor C1 and one end of the resistor R2, and the other end of the resistor R2 is connected to one end of the resistor R3, the gate of the P-channel junction field effect transistor Q5, and the collectors of the transistor Q3 and the transistor Q4; the drain of the P-channel junction field effect transistor Q5 is connected to the base of the transistor Q3 and the transistor Q4, and the source is connected to the other end of the resistor R3 and the resistor R4.

[0025] The Darlington compound tube includes a transistor Q6, a transistor Q7, a transistor Q8, a transistor Q9, a resistor R5, a resistor R6, a resistor R7, and a resistor R8;

[0026] One end of the resistor R5, the emitter of the transistor Q7, and the collectors of the transistors Q8 and Q9 are all connected to the input voltage VIN end, the other end of the resistor R5 is connected to the collector of the transistor Q6 and the base of the transistor Q7, the collector of the transistor Q7 is connected to one end of the resistor R6, the bases of the transistors Q8 and Q9, and the emitters of the transistors Q8 and Q9 are connected to one end of the resistor R7 and the resistor R8, respectively; the base of the transistor Q6 is connected to the input current I3 end, and the emitter is connected to the other end of the resistor R6 and then connected to the reference power supply VOUT2 end.

[0027] The current and voltage sampling circuit includes a resistor R10, a resistor R11, and a resistor R12;

[0028] One end of the resistor R10 is connected to the emitter of the transistor Q4, and the other end is connected to one end of the resistor R11 and the emitter of the transistor Q3; the other end of the resistor R11 is connected to one end of the resistor R12 and the other end of the resistor R8; the other end of the resistor R12 is connected to the other end of the resistor R7 and the reference power supply VOUT.

[0029] The overvoltage protection circuit includes a voltage stabilizing diode Z1, a voltage stabilizing diode Z2, and a resistor R9;

[0030] The cathode of the voltage zener diode Z1 is connected to the input voltage VIN terminal, the anode is connected to the cathode of the voltage zener diode Z2 through the resistor R9, and the anode of the voltage zener diode Z2 is connected to one end of the resistor R10 and the emitter of the crystal terminal Q4.

[0031] The capacitor C1 is a Miller capacitor;

[0032] Specifically, the Miller capacitor can be a silicon nitride capacitor, a silicon oxide capacitor, or a metal plate capacitor; its function is to be used for phase compensation and loop stabilization to prevent the circuit from oscillating when overcurrent or overvoltage protection occurs.

[0033] Specifically, in the overcurrent protection circuit, when the P-channel junction field effect transistor Q5 is used as a large resistor, it is used to provide bias for transistor Q3 and transistor Q4, stabilize the base current of transistor Q3 and transistor Q4, greatly improve the stability of transistor Q3 and transistor Q4, and solve the problem that the switch base of transistor Q3 and transistor Q4 is disturbed by fluctuations in the complex circuit environment, making the safe working area circuit more stable.

[0034] Example:

[0035] The working scenario of the safe working area protection circuit of the utility model is:

[0036] Working scenario 1: When the voltage of the input voltage VIN is too large, the voltage-stabilizing diode Z1 is broken down, and then the voltage-stabilizing diode Z2 is broken down through the resistor R9, which will cause a large voltage drop on the resistor R10. The voltage above the resistor R10 is high, which directly causes the emitter voltage of the transistor Q4 to become high. When the transistor Q4 is not turned on, the collector voltage of the transistor Q3 and the voltage at the right end of the resistor R2 increase at the same time, causing the transistor Q2 to turn on. The input current I3 directly passes through the resistor R1 and the resistor Q2 to the ground. The transistor Q1 serves as an amplifier for the transistor Q2. This structural design perfectly combines the overvoltage protection circuit with the overcurrent protection circuit as a safe working area protection circuit, and they no longer work separately.

[0037] Working scenario 2: When the input voltage VIN current is too large or the output current is too large, the large current through transistor Q9 and resistor R8 passes through sampling resistor R12 and is sampled by resistor R12. At the same time, the large voltage drop of resistor R12 causes resistor R11 to also have a large voltage drop, which increases the positive terminal above resistor R11. When the voltage-stabilizing diode Z1 and the voltage-stabilizing diode Z2 are not turned on, the voltage above resistor R11 becomes high, causing the emitter potential of transistor Q3 to increase, so that the collector voltage of transistor Q3 and the right end voltage of resistor R2 increase at the same time. Similar to the process of working scenario 1, transistor Q2 and transistor Q1 start to work, so that the overcurrent protection circuit starts to work. This design integrates the functions of the overvoltage protection circuit and the overcurrent protection circuit, and forms a constraint relationship. It has the functions of overvoltage and overcurrent protection, and can limit the safe working area or safe power. Because the idea of ​​functional integration is adopted, it also saves chip area and improves integration.

Claims

1. A safe operating area protection circuit suitable for a voltage-stabilizing integrated circuit, characterized in that: It comprises an overcurrent protection circuit, a Darlington compound tube, a current and voltage sampling circuit and an overvoltage protection circuit which are connected in sequence; the overcurrent protection circuit is also connected to the current and voltage sampling circuit and the overvoltage protection circuit; the positive end of the Darlington compound tube is connected to the input voltage VIN end, and the negative end is connected to the reference power supply VOUT2 end; the positive end of the overcurrent protection circuit is connected to the input current I3 end, and the negative end is connected to the reference power supply VOUT2 end; the negative end of the current and voltage sampling circuit is connected to the reference power supply VOUT end.

2. A safe operating area protection circuit suitable for a voltage-stabilizing integrated circuit as claimed in claim 1, characterized in that: The overcurrent protection circuit includes a transistor Q1, a transistor Q2, a transistor Q3, a transistor Q4, a P-channel junction field effect transistor Q5, a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a capacitor C1; The emitter of the transistor Q1, the resistor R1 and one end of the resistor R4 are all connected to the input current I3 end; the base of the transistor Q1 is connected to the other end of the resistor R1, one end of the capacitor C1 and the collector of the transistor Q2, and the collector is connected to the emitter of the transistor Q2 and the reference power supply VOUT2 end; the base of the transistor Q2 is connected to the other end of the capacitor C1 and one end of the resistor R2, and the other end of the resistor R2 is connected to one end of the resistor R3, the gate of the P-channel junction field effect transistor Q5, and the collectors of the transistor Q3 and the transistor Q4; the drain of the P-channel junction field effect transistor Q5 is connected to the base of the transistor Q3 and the transistor Q4, and the source is connected to the other end of the resistor R3 and the resistor R4.

3. A safe operating area protection circuit suitable for a voltage-stabilizing integrated circuit as claimed in claim 1, characterized in that: The Darlington compound tube includes a transistor Q6, a transistor Q7, a transistor Q8, a transistor Q9, a resistor R5, a resistor R6, a resistor R7, and a resistor R8; One end of the resistor R5, the emitter of the transistor Q7, and the collectors of the transistors Q8 and Q9 are all connected to the input voltage VIN end, the other end of the resistor R5 is connected to the collector of the transistor Q6 and the base of the transistor Q7, the collector of the transistor Q7 is connected to one end of the resistor R6, the bases of the transistors Q8 and Q9, and the emitters of the transistors Q8 and Q9 are connected to one end of the resistor R7 and the resistor R8, respectively; the base of the transistor Q6 is connected to the input current I3 end, and the emitter is connected to the other end of the resistor R6 and then connected to the reference power supply VOUT2 end.

4. A safe operating area protection circuit suitable for a voltage-stabilizing integrated circuit as claimed in claim 1, characterized in that: The current and voltage sampling circuit includes a resistor R10, a resistor R11, and a resistor R12; One end of the resistor R10 is connected to the emitter of the transistor Q4, and the other end is connected to one end of the resistor R11 and the emitter of the transistor Q3; the other end of the resistor R11 is connected to one end of the resistor R12 and the other end of the resistor R8; the other end of the resistor R12 is connected to the other end of the resistor R7 and the reference power supply VOUT.

5. A safe operating area protection circuit suitable for a voltage-stabilizing integrated circuit as claimed in claim 1, characterized in that: The overvoltage protection circuit includes a voltage stabilizing diode Z1, a voltage stabilizing diode Z2, and a resistor R9; The cathode of the voltage zener diode Z1 is connected to the input voltage VIN terminal, the anode is connected to the cathode of the voltage zener diode Z2 through the resistor R9, and the anode of the voltage zener diode Z2 is connected to one end of the resistor R10 and the emitter of the crystal terminal Q4.

6. A safe operating area protection circuit suitable for a voltage-stabilizing integrated circuit as claimed in claim 2, characterized in that: The capacitor C1 is a Miller capacitor.

7. A safe operating area protection circuit suitable for a voltage-stabilizing integrated circuit as claimed in claim 2, characterized in that: The P-channel junction field effect transistor Q5 is used to provide bias for the transistor Q3 and the transistor Q4, so as to achieve the stabilization function of the base current of the transistor Q3 and the transistor Q4.