The LTC1771 is a high efficiency current mode step-down DC/DC controller that draws as little as 10µA DC supply current to regulate the output at no load while maintaining high efficiency for loads up to several amps.The LTC1771 drives an external P-channel power MOSFET using a current mode, constant off-time architecture. An external sense resistor is used to program the operating current level. Current mode control provides short-circuit protection, excellent transient response and controlled start-up behavior. Burst Mode operation enables the LTC1771 to maintain high efficiency down to extremely low currents. Shutdown mode further reduces the supply current to a mere 2µA. For low noise applications, Burst Mode operation can be easily disabled with the MODE pin.Wide input supply range of 2.8V to 18V (20V maximum) and 100% duty cycle operation for low dropout make the LTC1771 ideal for a wide variety of battery-powered applications where maximizing battery life is important.The LTC1771’s availability in both 8-lead MSOP and SO packages provides for a minimum area solution.ApplicationsCellular Telephones and Wireless Modems1- to 4-Cell Lithium-Ion-Powered ApplicationsPortable InstrumentsBattery-Powered EquipmentBattery ChargersScanners