LTC1771E

Final Electrical Specifications LTC1771 Low Quiescent Current High Efficiency Step-Down DC/DC Controller FEATURES s s s s s s s s s DESCRIPTIO February 2000 s s s s Very Low Standby Current: 10µA Available in Space-Saving 8-Lead MSOP Package High Output Currents Wide VIN Range: 2.8V to 20V Operation VOUT Range: 1.23V to 18V High Efficiency: Over 93% Possible ± 2% Output Accuracy Very Low Dropout Operation: 100% Duty Cycle Current Mode Operation for Excellent Line and Load Transient Response Defeatable Burst ModeTM Operation Short-Circuit Protected Optional Programmable Soft-Start Micropower Shutdown: IQ = 2µA The LTC®1771 is a high efficiency current mode stepdown 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 ma...