The CAT6219 is a 500mA CMOS low dropout regulator that provides fast response time during load current and line voltage changes. The quick-start feature allows the use of an external bypass capacitor to reduce the overall output noise without affecting the turn-on time of just 150s. With zero shutdown current and low ground current of 55A typical, the CAT6219 is ideal for batteryoperated devices with supply voltages from 2.3V to 5.5V. An internal under voltage lockout circuit disables the output at supply voltages under 2.15V typical. The CAT6219 offers 1% initial accuracy and low dropout voltage, 300mV typical at 500mA. Stable operation is provided with a small value ceramic capacitor, reducing required board space and component cost.