A triple output 3.3V, 5V, and 12V high efficiency notebook power supply is described.
Step-down switching regulator
The new LTC1142 is a dual 5V and 3.3V synchronous step-down switching regulator controller featuring automatic Burst Mode operation to maintain high efficiencies at low output currents. Two independent regulator sections, each driving a pair of complementary MOSFETs, may be shut down separately to less than 20μA/output. This feature is an absolute necessity to maximize battery life in portable applications. Additionally, the input voltage to each regulator section can be individually connected ...