Power-on reset circuit

Abstract

The invention discloses a power-on reset circuit, comprising: a 2VTH level detection circuit, a power supply voltage divider and hysteresis comparison circuit, a logic circuit and a counter; the 2VTH level detection circuit is used to detect whether the power supply voltage is greater than VTHN+VTHP; The voltage and hysteresis comparison circuit is used to generate the power supply voltage divider, and compares whether the power supply voltage divider is greater than the bandgap voltage of the chip; the logic circuit is used to start the counter when the power supply voltage is greater than VTHN+VTHP and the power supply voltage divider is greater than the bandgap voltage For counting, the counter is also connected to the clock, and the reset signal is released from low level to high level after a first time delay. The invention makes up for the deficiency that the existing power-on reset circuit cannot generate a power-on reset signal in both the slow power-on process and the fast power-on process, and satisfies the need to effectively generate the power-on reset signal in both the slow power-on process and the fast power-on process. electrical reset signal on demand.

Description

technical field [0001] The invention belongs to the field of electronic technology, in particular to a power-on reset circuit. Background technique [0002] When the chip is powered on, a reset signal needs to be generated to reset the internal registers. Commonly used power-on reset circuits include capacitor-resistor structures and level-triggered structures. The capacitor-resistance structure uses the time constant of the capacitor-resistance product as a delay to generate a reset signal. The advantage is that it does not consume power after the power-on process is over. The disadvantage is that it cannot generate a reset signal during the slow power-on process; the level-triggered structure converts the power supply voltage The divided voltage is compared with the internal bandgap voltage of the chip. When the divided voltage of the power supply voltage is greater than the bandgap (bandgap reference) voltage, the power-on reset signal is released. The advantage is that t...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to overcome the defect that the existing power-on reset circuit cannot generate a power-on reset signal in both the slow power-on process and the fast power-on process, and provide a A power-on reset circuit that can effectively generate a power-on reset signal during the power-up process and has high reliability and strong anti-interference ability

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