LTC3857-1 FUNCTIONAL DIAGRAM INTVCC VIN DUPLICATE FOR SECOND CONTROLLER CHANNEL BOOST DB CB TG DROP TOP PGOOD1 + OUT C 0.88V IN D DET BOT – SW TOP ON VFB1 S Q + INTVCC R – Q 0.72V SWITCH BG SHDN LOGIC BOT C PGND OUT FREQ 20μA VOUT VCO CLK2 + R 0.425V SENSE CLK1 SLEEP L – ICMP IR – + C PFD LP + – – + + – 3mV SENSE+ SYNC 2.7V PLLIN/MODE DET 0.55V SENSE– 100k SLOPE COMP VFB R + B VIN EA – 0.80V R TRACK/SS A EXTVCC + OV – C 0.88V C ITH 5.1V 5.1V 0.5μA LDO LDO C R EN EN C2 C SHDN 1μA + RST FOLDBACK TRACK/SS 11V 2(VFB) – 4.7V SHDN CSS SGND INTVCC RUN 38571 FD 38571fc 10 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS FUNCTIONAL DIAGRAM OPERATION APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION REVISION HISTORY TYPICAL APPLICATION RELATED PARTS
