LTC3613 PIN FUNCTIONSRUN (Pin 26): Digital Run Control Input. RUN self biases detected or MODE/PLLIN is tied to INTVCC, forced continu- high with an internal 1.3μA pull-up. Forcing RUN below ous mode operation is selected. Tying this pin to SGND 1.2V disables switching. Taking RUN below 0.75V shuts allows discontinuous pulse-skipping mode operation at down all bias and places the LTC3613 into micropower light loads. shutdown mode of approximately 15μA. SVIN (Pin 32): Signal Input Supply. This pin powers the EXTVCC (Pin 30): External VCC Input. When EXTVCC exceeds internal control circuitry. 4.6V, an internal switch connects this pin to INTVCC and INTV shuts down the internal regulator so that the controller and CC (Pins 33, 34): Internal 5.3V Regulator Output. The driver and control circuits are powered from this voltage. gate drive power is drawn from EXTVCC. EXTVCC should Decouple this pin to power ground with a minimum of not exceed VIN. 4.7μF ceramic capacitor (CVCC). The anode of the Schottky MODE/PLLIN (Pin 31): External Clock Synchronization diode, DB, connects to this pin. Input and/or Forced Continuous Mode Input. When an PGND (Pins 36-44): Power Ground Connection. Connect external clock is applied to this pin, the rising switching this pin as close as practical to the (–) terminal of C cycle will be synchronized with the rising edge of the VCC and the (–) terminal of C external clock. Additionally, this pin determines operation IN. under light load conditions. When either a clock input is 3613fa 9