Under-voltage protection circuit with low starting current

Abstract

The invention provides an under-voltage protection circuit with a low starting current, which comprises a voltage detector used for detecting the voltage of the input power, a circuit used for amplifying detection signals and a circuit used for generating a constant current source. The voltage detector of the input power comprises three diodes, a PMOS crystal tube and a resister; the output signals of the detection circuit are amplified by an amplifier which comprises an NMOS crystal tube and the resister; the amplification results are output to a Schmitt trigger; and the output signals of the Schmidt trigger are output after being buffered by two phase inverters, and are used as the control signals to detect whether the voltage of the power supply is the under-voltage. The under-voltage protection circuit can be used for high-voltage detection; the structure is simple; and the starting current is low, thus being helpful to improve the product performances under the condition of low cost.

Description

Technical field: [0001] The application relates to an undervoltage protection circuit with low starting current. Background technique: [0002] Undervoltage protection is a commonly used protection function in integrated circuits. Its function is that when the power supply voltage of the chip drops to a certain level, the chip should sense this situation in time and take corresponding protection measures. After the power supply voltage returns to the normal value The boot chip works fine. [0003] The traditional under-voltage protection circuit consists of a voltage-dividing resistor network, a comparator, a reference voltage source, and control logic. Such as figure 1 As shown, the protection circuit includes a comparator 11, a logic control module 12, a reference voltage source 13 and a sampling resistor network 14 composed of resistors R1 and R2. The sampling resistor network 14 samples the voltage of VDD and sends the result to the comparator 11. One input terminal i...

AI Technical Summary

Problems solved by technology

In terms of performance and area requirements, the above undervoltage protection circuit structure will be difficult to adapt to such applications

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