The LTC3822 is a synchronous step-down switching regulator controller that drives external N-channel power MOSFETs using few external components. The constant frequency current mode architecture with MOSFET VDS sensing eliminates the need for sense resistors and improves efficiency. A maximum duty cycle of 99% provides low dropout operation. The switching frequency can be programmed up to 750kHz, allowing the use of small surface mount inductors and capacitors.