A power-on-reset circuit with precisely triggered threshold voltages

A power-on-reset (POR) circuit, which is an important block in mixed-signal integrated circuits, is used for the correct initialization of critical logic states in digital blocks of mixed-signal circuits. A POR circuit with precisely triggered threshold voltages is proposed. The circuit is designed in a 0.18 μm CMOS technology with a maximum 4 μA quiescent current. The output signal of the proposed circuit is also used to precisely detect whether the power supply is power-on or brown-out. The proposed POR circuit is insensitive to the power ramping time and tolerant to process variations. At typical corner, the proposed circuit reduces the quiescent current by more than 10× and layout area by 38% compared to the previously published designs.