A mobile communications device (50) includes a plurality of LDOs (30) for supplying a stable voltage to various circuits on the device. In a normal mode, the LDO's main bandgap voltage source (12) supplies a voltage to a main amplifier (16). During deep sleep mode, sleep logic (40) places the LDOs in a sleeping state, where a low current sleep bandgap voltage source (32) supplies a voltage to a smaller, sleep amplifier (36), which maintains a charge on capacitors (24, 26) for a fast transitions to a full ON state.