Linear regulator with current limiting short circuit protection function

Abstract

The invention relates to a linear regulator with a current limiting short circuit protection function. The linear regulator comprises a starting circuit, a reference voltage circuit, a current sampling circuit, a voltage sampling circuit, a comparison amplifier circuit, a short circuit protection circuit and a control tube V2, wherein the control tube V2 is connected between a direct current input end XB1 and a voltage regulation output end XB2; the starting circuit transmits an input voltage source into the reference voltage circuit; the reference voltage circuit provides regulated reference voltage for the comparison amplifier circuit to use; the output end of the control tube V2 is connected in series with the current sampling circuit; the current sampling circuit feeds a sampled output current signal back to the comparison amplifier circuit; the voltage sampling circuit feeds a sampled output voltage signal back to the comparison amplifier circuit; the comparison amplifier circuit processes the output current signal and the output voltage signal, and transmits the processed output current signal and the processed output voltage signal into the control end of the control tube V2, so that the control tube works in a linear region to fulfill the aim of current limiting voltage regulation; and the short circuit protection circuit processes the acquired output voltage signal by a photoelectric coupler B2, and transmits the processed output voltage signal into the control end of the control tube V2, so that the control tube V2 is regulated from the linear region to a switching-off region to fulfill the aim of short circuit protection.

Description

technical field [0001] The invention relates to a linear voltage regulator, in particular to a linear voltage regulator with current-limiting short-circuit protection. Background technique [0002] The traditional electric voltage stabilizer relies on the beating of the relay to stabilize the output voltage. When the grid voltage fluctuates, the automatic correction circuit of the electric voltage stabilizer is activated, so that the internal relay acts to force the output voltage to remain near the set value. This circuit The advantage is that the circuit is simple, and the disadvantage is that the accuracy of voltage regulation is not high and every time the relay jumps and shifts, the power supply will be interrupted instantaneously and spark interference will occur. [0003] The compensation of system stability still mainly depends on the zero point produced by the output capacitor ESR, so the requirements for the output capacitor ESR are very strict, and the value of th...

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Problems solved by technology

In addition, during the entire working process and stable variation range, ESR must reside in a cross-border region, the sensitivity of LDO to ESR, and the high reliability of ESR to temperature and frequency are more likely to cause oscillation than any other reason, so A large, expensive capacitor is required to solve this problem, so a new compensation scheme is required

[0004] In addition, in practice, it is often encountered that there are various short-circuits with the power supply or ground due to misoperation, which may easily cause a short circuit, and in severe cases, the circuit will be burned, accidents will occur, and the safety performance is low.

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