Datasheet LTC3548A (Analog Devices) - 6

LTC3548A
PIN FUNCTIONS VFB1 (Pin 1):
Output Feedback. Receives the feedback volt-
SW2 (Pin 7):
Regulator 2 Switch Node Connection to the age from the external resistive divider across the output. Inductor. This pin swings from VIN to GND. Nominal voltage for this pin is 0.6V.
POR (Pin 8):
Power-On Reset. This common-drain logic
RUN/SS1 (Pin 2):
Regulator 1 Enable and Soft-Start Input. output is pulled to GND when the output voltage is not Forcing this pin to VIN enables regulator 1, while forcing it within ±8.5% of regulation and goes high after 216 clock to GND causes regulator 1 to shut down. Connect external cycles when both channels are within regulation. RC network with desired time-constant to enable soft-start
RUN/SS2 (Pin 9):
Regulator 2 Enable and Soft-Start Input. feature. This pin must be driven; do not float. Forcing this pin to VIN enables regulator 2, while forcing it
VIN (Pin 3):
Main Power Supply. Must be closely decoupled to GND causes regulator 2 to shut down. Connect external to GND. RC network with desired time-constant to enable soft-start feature. This pin must be driven; do not float.
SW1 (Pin 4):
Regulator 1 Switch Node Connection to the Inductor. This pin swings from VIN to GND.
VFB2 (Pin 10):
Output Feedback. Receives the feedback voltage from the external resistive divider across the output.
NC (Pin 5):
No Connect. This pin is not connected inter- Nominal voltage for this pin is 0.6V. nally. Connect to ground on PCB for shielding purposes.
Exposed Pad (GND) (Pin 11):
Power Ground. Connect to
MODE/SYNC (Pin 6):
Combination Mode Selection and the (–) terminal of C Oscillator Synchronization. This pin controls the opera- OUT, and (–) terminal of CIN. Must be soldered to electrical ground on PCB. tion of the device. When tied to VIN or GND, Burst Mode operation or pulse-skipping mode is selected, respectively. Do not float this pin. The oscillation frequency can be synchronized to an external oscillator applied to this pin and pulse-skipping mode is automatically selected. 3548afa 6