Nordic Semiconductor ASA
VOLTAGE REGULATOR

Abstract:

A low-dropout voltage regulator arranged to regulate an output voltage (VDD) comprising: a differential amplifier portion including a first amplifier input connected to a reference voltage (VREF), a second amplifier input, and a differential output which is determined by a difference between the reference voltage and a voltage on the second amplifier input; an output portion arranged to provide a regulator output voltage controlled by the differential output of the differential amplifier portion, wherein the second amplifier input is connected to or derived from the regulator output voltage; a first biasing portion arranged to provide a first bias current to the differential amplifier portion which depends on an external load current; and a second biasing portion comprising a DC-blocking capacitor (C0) connected to the output portion so as to provide a second bias current to the differential amplifier portion which depends on the rate of change of the output voltage.