LTC3417A-1 PIN FUNCTIONSPHASE (Pin 14/Pin 17): Selects 1A regulator switching PGND1 (Pin 16/Pin 19): Ground for SW1 N-Channel Driver. phase with respect to 1.5A regulator switching. Set to PGND2, GNDD (Pins 1,10,11,20): TSSOP Package Only. VIN, the 1.5A regulator and the 1A regulator are in phase. Ground for SW2 N-channel driver and digital ground for When PHASE is at 0V, the 1.5A regulator and the 1A circuit. regulator are switching 180 degrees out-of-phase. Do not fl oat this pin. Exposed Pad (Pin 17/Pin 21): PGND2, GNDD. Ground for SW2 N-channel driver and digital ground for circuit. The SW1 (Pin 15/Pin 18): Switch Node Connection to the Exposed Pad must be soldered to PCB ground. Inductor for the 1.5A Regulator. This pin swings from VIN1 to PGND1. FUNCTIONAL DIAGRAM1.5A REGULATOR ITH1 I VIN1 + TH LIMIT – + VFB1 – + – VB SLOPE COMPENSATION 0.752V + ANTI-SHOOT- SW1 – THROUGH + + LOGIC – 0.848V – – PGND1 + RUN1 POR VOLTAGE V REFERENCE IN2 DELAY RUN2 PHASE SYNC/MODE OSCILLATOR FREQ + PGND2 – – 0.848V – LOGIC + + – SW2 ANTI-SHOOT- THROUGH + 0.752V SLOPE COMPENSATION – + VFB2 – VB + – + ITH 1A REGULATOR I LIMIT TH2 VIN2 3417A-1 BD 3417a1fa 7