The ADP151 is an ultralow noise， low dropout linear regulator that operates from 2.2 V to 5.5 V and provides up to 200 mA of output current. The low 140 mV dropout voltage at 200 mA load improves efficiency and allows operation over a wide input voltage range. Using an innovative circuit topology， the ADP151 achieves ultralow noise performance without the necessity of a bypass capacitor， making it ideal for noise-sensitive analog and RF applications. The ADP151 also achieves ultralow noise performance without compromising PSRR or transient line and load performance. The low 265 μA of quiescent current at 200 mA load makes the ADP151 suitable for battery-operated portable equipment. The ADP151 also includes an internal pull-down resistor on the EN input. The ADP151 is specifically designed for stable operation with tiny 1 μF， ±30% ceramic input and output capacitors to meet the requirements of high performance， space constrained applications. The ADP151 is capable of 16 fixed output voltage options， ranging from 1.1 V to 3.3 V. Short-circuit and thermal overload protection circuits prevent damage in adverse conditions. The ADP151 is available in tiny 5-lead TSOT， 6-lead LFCSP， and 4-ball， 0.4 mm pitch， halide-free WLCSP packages for the smallest footprint solution to meet a variety of portable power application requirements.