Short-circuit protection circuit with high-side output
By using a short-circuit protection circuit composed of transistors and resistors, the problem of high cost of high-side driver chips is solved, achieving low-cost high-side output and stability protection.
Patent Information
- Application Number
- CN202423157050.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2034-12-19
AI Technical Summary
Traditional high-side driver chips are expensive, which leads to higher costs for short-circuit protection circuits. The market needs a cost-effective alternative.
A short-circuit protection circuit composed of simple components such as transistors Q1, Q2, Q3, and resistors R129, R130, and R131 achieves high-side output and short-circuit protection by controlling the base current of the transistors, thus preventing transistor Q2 from burning out.
This achieves low-cost high-side output short-circuit protection, avoiding short-circuit damage to transistor Q2 and improving circuit stability and cost-effectiveness.
Smart Images
Figure CN223583793U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to circuit protection technical field especially is related to a short circuit protection circuit with high side output. BACKGROUND
[0002] Many car switches have high side output function, and the traditional method is to use high side drive chip with short circuit protection, however, such drive chip is high in price, resulting in large cost of short circuit protection circuit, especially under the condition of current market needs to compress cost, therefore, a high cost performance short circuit protection circuit is urgently needed to replace high side drive chip. SUMMARY
[0003] The utility model discloses a short circuit protection circuit with high side output, which realizes high side output with short circuit protection function by controlling the base current of the transistor, is low in cost and good in performance.
[0004] The utility model discloses a short circuit protection circuit with high side output, which realizes high side output with short circuit protection function by controlling the base current of the transistor, is low in cost and good in performance.
[0005] Further setting, still include resistance R302, resistance R302's first end control signal input end, resistance R302's second end connects the base of triode Q1.
[0006] Further setting, still include capacitor C115, capacitor C115 first end connects the collector of triode Q2, and capacitor C115's second end connects the ground.
[0007] Further setting, still include resistance R1 and resistance R2, resistance R1 first end connects resistance R302, and resistance R1's second end connects the base of triode Q1 and resistance R2's first end, and resistance R2's second end connects the ground.
[0008] Compared with the prior art, the circuit of this utility model only requires simple components for short-circuit protection and can output a high level. Compared with the existing technology that uses driver chips, it effectively controls costs. When the control signal input terminal is high, transistor Q1 is turned on, and the base of transistor Q2 forms a path through transistor Q1, so transistor Q2 is turned on and the collector outputs a high level. When the current increases, the voltage drop across resistor R131 increases, at which time transistor Q3 is turned on, which increases the current flowing through resistor R129, thus increasing the voltage drop across it and increasing the base voltage of transistor Q2. This reduces the base and emitter voltage drop of transistor Q2, reduces the base current of transistor Q2, and decreases the conduction capability of transistor Q2, preventing transistor Q2 from burning out due to short power supply. When the signal input terminal is closed, the base of transistor Q2 has a stable level through resistor R130, preventing circuit instability. Attached Figure Description
[0009] Figure 1 This is a structural schematic diagram of a specific embodiment of the present utility model. Detailed Implementation
[0010] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0011] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0012] like Figure 1 As shown, a short-circuit protection circuit with high-side output includes transistors Q1, Q2, and Q3, resistors R129, R130, and R131. The base of transistor Q1 is connected to the control signal input terminal, the emitter of transistor Q1 is grounded, and the collector is connected to the first terminal of resistor R129. The second terminal of resistor R129 is connected to the base of transistor Q2, the collector of transistor Q3, and the first terminal of resistor R130. The emitter of transistor Q2 is connected to the base of transistor Q3 and the first terminal of resistor R131. The collector of transistor Q2 is connected to the high-level output terminal, and the emitter of transistor Q3 is connected to the second terminal of resistor R130, the second terminal of resistor R131, and the voltage input terminal.
[0013] Further setting, still include resistance R302, resistance R302's first end control signal input terminal, resistance R302's second end connects triode Q1's base.
[0014] Further setting, still include capacitor C115, capacitor C115's first end connects triode Q2's collector, capacitor C115's second end connects ground.
[0015] Further setting, still include resistance R1 and resistance R2, resistance R1's first end connects resistance R302, resistance R1's second end connects triode Q1's base and resistance R2's first end, resistance R2's second end connects ground.
[0016] Compared with the prior art, the circuit of the utility model only needs simple devices to carry out short circuit protection, realizes output high level by controlling triode base current, effectively controls cost compared with the prior art that adopts driving chip, when the control signal input terminal is high level, triode Q1 is turned on, the base of triode Q2 forms a passway through triode Q1, triode Q2 is turned on, and the collector outputs high level to the outside, when the current becomes large, the voltage drop between resistance R131 becomes large, generates 0.7V voltage drop, at this time, triode Q3 is turned on and generates negative feedback, so that the current through resistance R129 becomes large, the voltage drop between two ends becomes large, the base voltage of triode Q2 becomes high, thereby reducing the base and emitter voltage drop of triode Q2, reducing the base current of triode Q2, so that the turn-on ability of triode Q2 decreases, avoiding triode Q2 short power supply and burning out, when the signal input terminal is closed, the base of triode Q2 has a stable level through resistance R130, avoiding unstable circuit.
Claims
1. A short-circuit protection circuit with high-side output, characterized in that, The system includes transistors Q1, Q2, and Q3, resistors R129, R130, and R131. The base of transistor Q1 is connected to the control signal input terminal, the emitter of transistor Q1 is grounded, and the collector is connected to the first terminal of resistor R129. The second terminal of resistor R129 is connected to the base of transistor Q2, the collector of transistor Q3, and the first terminal of resistor R130. The emitter of transistor Q2 is connected to the base of transistor Q3 and the first terminal of resistor R131. The collector of transistor Q2 is connected to the high-level output terminal. The emitter of transistor Q3 is connected to the second terminal of resistor R130, the second terminal of resistor R131, and the voltage input terminal.
2. The short-circuit protection circuit with high-side output according to claim 1, characterized in that, It also includes a resistor R302, the first end of which is the control signal input terminal, and the second end of which is connected to the base of the transistor Q1.
3. The short-circuit protection circuit with high-side output according to claim 1 or 2, characterized in that, It also includes a capacitor C115, the first end of which is connected to the collector of transistor Q2, and the second end of the capacitor C115 is grounded.
4. The short-circuit protection circuit with high-side output according to claim 2, characterized in that, It also includes resistors R1 and R2. The first end of resistor R1 is connected to resistor R302, the second end of resistor R1 is connected to the base of transistor Q1 and the first end of resistor R2, and the second end of resistor R2 is grounded.