Low power LDO with fast load transient response based on quick response circuit

In this work, we propose a design technique of low power fully CMOS low-dropout voltage regulator (LDO) based on quick response (QR) circuit to improve the load transient response. Implemented in 0.18 mum CMOS technology, the LDO with proposed QR circuit can achieve a fast load transient responses with less transient overshoot or undershoot when driving a large load current. For 1 muF decoupling capacitor and 0.1 mA-150 mA load current change, the output undershoot and overshoot are 196 mV and 172 mV while the settling time is approximately 60 mus and 65 mus respectively . The proposed circuit dissipates a very low static power, with only 8.5 muA for light load and 35 muA for heavy load for output voltage VOUT = 1.2 V and input voltage VDD = VOUT + 1.0 V . This includes the reference circuit, the over current protection circuit as well as the feedback network.