A low voltage auto-reconfigured power-on-reset/bandgap reference circuit

Abstract

In this paper, a low voltage auto-reconfigured power-on-reset/bandgap reference circuit is proposed. During initial power up, the circuit utilizes a transconuductor and a bandgap core to detect the power-up supply voltage level (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TPU</sub> ) precisely with minimum temperature and process dependence. No precise reference voltage is required. After a power-up signal is issued, the circuit is reconfigured into a bandgap circuit with a precise reference output voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ref</sub> ) for the use of other circuits. Based on a 0.18μm CMOS process, a V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TPU</sub> of 999.5mV with variations within +0.18% and -0.15% for different process corners and temperatures (-20°C to +120°C) was obtained. After power up, a V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ref</sub> of 599.4mV with variations within +0.15% and -0.46% was achieved.