compensateLDOA USER’S GUIDE TO COMPENSATING LOW-DROPOUT REGULATORS Chester Simpson National Semiconductor 2900 Semiconductor Drive M/S D2740 Santa Clara, Ca. 95052-8090 (408) 721-7501 The explosive proliferation of batterypowered equipment in the past decade has accelerated the development and usage of Low-Dropout voltage regulators (sometimes referred to as PNP voltage regulators). Compared to the standard NPN regulator, the Low-Dropout Regulator (LDO) can hold its output voltage in regulation with much less voltage across it: the NPN requires about 2V of “headroom” to regulate, while the LDO will typically work with less than 500 mV of input-to-output voltage differential. The reduced input voltage requirement of an LDO i s advantageous in batterypowered systems, since it translates directly into f……