| Description & Applications | 600 kHz PWM/PFM Step−Down DC−DC Controller • High Efficiency 92%, Typical • Low Quiescent Bias Current of 50 A (Typical at PFM Mode with No Load) • Output Voltage Options from 1.8 V to 3.3 V with High Accuracy 2.0% • Low Output Voltage Ripple, 50 mV, Typical • PWM Switching Frequency at 600 kHz • Automatic PWM/PFM Switchover at Light Load Condition • Very Low Dropout Operation, 100% Max. Duty Cycle • Chip Enable Pin with On−Chip 150 nA Pullup Current Source • Low Shutdown Current, 0.3 A, Typical • Input Voltage Range from 2.45 V to 5.5 V • Built−in Soft−Start • Internal Undervoltage Lockout (UVLO) Protection • Low Profile and Minimum External Components • Micro Miniature TSOP−5 Package • Pb−Free Packages are Available • Personal Digital Assistant (PDA) • Camcorders and Digital Still Camera • Hand−Held Instrument • Distributed Power System • Computer Peripheral |