LTC3602 PIN FUNCTIONS FE/UF PackageSYNC/MODE (Pin 1/Pin 4): Mode Select and External be programmed by connecting a capacitor between this Clock Synchronization Input. pin and ground. Leave this pin fl oating to use the internal 1ms soft-start clamp. Do not tie this pin to INTV PGOOD (Pin 2/Pin 5): Power Good Output. Open-drain CC or to PV logic output that is pulled to ground when the output volt- IN. age is not within ±10% of regulation point. PGND (Pins 8, 9, 10/Pins 12, 13, 14, 15): Power Ground. RT (Pin 3/Pin 6): Frequency Set Pin. SW (Pins 11, 12, 13/Pins 16, 17, 18, 19): Switch Node ITH (Pin 4/Pin 7): Error Amplifi er Compensation Point. Connection to the Inductor. VFB (Pin 5/Pin 8): Feedback Pin. BOOST (Pin 14/Pin 20): Bootstrapped Supply to the Top SGND (Pin 17/Pin 9, Pin 21): Signal Ground. Side Floating Gate Driver. RUN (Pin 6/Pin 10): Run Control Input. This pin may be PVIN (Pin 15/Pins 1,2): Power Input Supply. Decouple tied to PVIN to enable the chip. this pin with a capacitor to PGND TRACK/SS (Pin 7/Pin 11): Tracking Input for the Controller INTVCC (Pin 16/Pin 3): Output of Internal 5V LDO. or Optional External Soft-Start Input. This pin allows the Exposed Pad (Pin 17/Pin 21): SGND. Exposed pad is start-up of VOUT to “track” the external voltage at this pin signal ground and must be soldered to the PCB. using an external resistor divider. An external soft-start can BLOCK DIAGRAM I BOOST TH INTVCC PVIN 1μA LDO 0.6V VOLTAGE REFERENCE SLOPE COMPENSATION RECOVERY TRACK/SS 1ms SOFT-START BCLAMP + ERROR + AMPLIFIER BURST + COMPARATOR MAIN – + + I-COMPARATOR VFB – SYNC/MODE – SW + – 0.54V + SW SLOPE COMPENSATION OSILLATOR – OVER-CURRENT SW COMPARATOR + + 0.66V LOGIC – PGND – REVERSE PGND PGOOD COMPARATOR + PGND – R RUN T SYNC/MODE 3602 BD 3602fb 6