A 54-nA Quiescent Current Capless LDO With −39-dB PSRR at 1 MHz Using a Load-Tracking Bandwidth Extension Technique

This brief presents a low-dropout regulator (LDO) with wide bandwidth and low quiescent current. The proposed LDO includes a load-tracking fast feedforward path for bandwidth extension and light load driving capability. The proposed technique allows for a wide bandwidth of 38.5 MHz with a small 400 fF compensation capacitor, and a quiescent current of 54 nA. The chip was fabricated using a 180-nm process with an active area of 0.0074 mm2. Because of the wide 38.5 MHz bandwidth at 10 mA, the power supply rejection ratio was −39 dB at 1 MHz and −24.5 dB at 10 MHz, with a 0.084 fs figure of merit.