The NCP551 series of fixed output low dropout (LDO) linear voltage regulators are designed for applications which require low quiescent current. The NCP551 series features an ultra-low quiescent current of 4.0 µA. Each device contains a voltage reference unit, an error amplifier, a PMOS power transistor, resistors for setting output voltage, current limit, and temperature limit protection circuits.The NCP551 has been designed to be used with low cost ceramic capacitors and requires a minimum output capacitor of 0.1 µF. The device is housed in the micro miniature TSOP-5 surface mount package. Standard voltage versions are 1.4, 1.5, 1.8, 2.5, 2.7, 2.8, 3.0, 3.3, and 5.0 V. Other voltages are available in 100 mV steps.