The SYNC pin can be configured as an input or as an output, depending on the configuration of the RT pin. If the RT pin is open or tied to AGND, the SYNC pin functions as an output. When operating as an output, the falling edge of the signal is one half of the switching cycle and approximately 180° out of phase with the rising edge of the PH pins. Thus, two TPS54350 devices operating in a system can share an input capacitor and draw ripple current at twice the frequency of a single unit.

If the RT pin is programmed with a resistor to AGND, the SYNC pin functions as an input. When operating as an input, the SYNC pin is a falling-edge triggered signal, and the resistor at the RT pin should be set to provide a frequency equal to 90 percent of the SYNC input frequency.