Power-on reset circuit

Abstract

The invention relates to a power-on reset circuit with high reliability and low power consumption. The circuit uses the mode of combining a comparator and a Schmitt trigger. Compared with a previous RC power-on reset circuit, the circuit of the invention has a smaller area, lower power consumption and higher repeated power-on reliability, and has the performance characteristics that power-on and power-off thresholds can be set and so on. The reset circuit of the invention can be used to completely solve the disadvantage of the traditional RC power-on reset circuit, and the disadvantage is thatif a reset pulse is wide, the capacitance value of a capacitor has to be increased and a domain area is increased too. A problem that capacitor charges can not be discharged immediately when a powersupply voltage drops rapidly to zero is solved, and continuous reset pulses generated when a power supply is not stable can be avoided. The circuit does not use the capacitor. When power down and power on are performed rapidly, reset can be effectively performed. Hspice software is used to simulate the circuit, when the power supply voltage is 3.3V, a power-on threshold is set to be 3V, a power-down threshold is set to be 2.8V, and slow power-on and rapid power-down conditions have a good reset effect.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a power-on reset circuit. Background technique [0002] In the field of integrated circuits, both digital integrated circuits and hybrid integrated circuits use reset circuits, such as flip-flops, registers and other circuits. During the power-on process of the circuit, due to the extremely unstable power supply of the digital circuit, during this period The logic of the digital circuit is disordered, and it is easy to produce wrong logic. Therefore, the initial stage after the digital circuit is powered on needs a definite state, that is, the reset state, which requires a power-on reset circuit with very good performance. The power-on reset circuit needs to generate a reset pulse after the power supply is stable, so that the internal digital circuit of the system can be fully and reliably reset by this reset pulse. A power-on reset circuit with good performance should also ha...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the above-mentioned deficiencies in the prior art, the present invention provides a new power-on reset circuit, which completely solves the traditional RC power-on reset circuit. If you want a wider reset pulse, you must increase the capacitance of the capacitor. The area will increase. When the power supply voltage drops to zero rapidly, the capacitor charge cannot be discharged immediately, and the circuit cannot generate reset pulse signals when the power supply is powered on at this time.

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