A Micropower Low-Dropout Regulator with a Programmable On-Chip Load Capacitor for a Low-Power Capacitive Sensor Interface

摘要

In this paper, a micropower low-dropout regulator (LDO) for a low-power capacitive sensor interface fabricated in a 0.25μm BiCMOS process is presented. The LDO with on-chip voltage and current references, and an on-chip programmable load capacitor, occupies an active silicon area of 0.18 mm~2. It is stable with zero load current over the load capacitance range from 0 to 1 nF. The input voltage range extends from 1.2 to 2.75 V, while the designed output voltage is 1.0 V. The measured quiescent current of the LDO including the on-chip references is 7.6μA. According to the measurements, the regulated output has a temperature coefficient (TC) of 57.2 ppm/°C, a line regulation of 2.71 mV/V, and a load regulation of 1.64 mV/mA. The rms output noise integrated over the bandwidth ranging from 1 Hz to 100 kHz is 1.365 mV.