LTC3873-5

LTC3873-5 No RSENSETM Constant Frequency Current Mode Boost/Flyback/SEPIC DC/DC Controller FEATURES n VIN and VOUT Limited Only by External Components n Internal or Programmable External Soft-Start n Constant Frequency 200kHz Operation n Adjustable Current Limit n Current Sense Resistor Optional n ±1.5% Voltage Reference Accuracy n Current Mode Operation for Excellent Line and Load Transient Response n 4.1V Undervoltage Threshold for Logic Level MOSFET Applications n Low Quiescent Current: 300μA n Low Profile (1mm) ThinSOTTM and (0.75mm) 2mm × 3mm DFN Package APPLICATIONS n Telecom Power Supplies n Automotive Power Supplies n PoE Applications DESCRIPTION The LTC®3873-5 is a constant frequency current mode controller for boost, flyback or SEPIC DC/DC converters designed to drive an N-channel MOSFET for high input and output voltage converter applications. The LTC3873-5 provides ±1.5% output voltage accuracy and consumes only 300μA quiescent current during normal operation and only 50μA during micropower start-up. Using a 9.3V internal shunt regulator, the LTC3873-5 can be powered from a high input voltage through a resistor or it can be powered directly from a low impedance DC voltage of 9V or less. Soft-start can be programmed using an external capacitor. The LTC3873-5 is available in 8-lead ThinSOT and 2mm × 3mm DFN packages. PARAMETER VCC UV+ VCC UV– LTC3873 8.4V 4V LTC3873-5 4.1V 2.9V L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. No ...