SLUSE80A September 2021 – November 2021 UCC14240-Q1
The ENA input pin and /PG output pin on the primary-side use 5-V TTL and 3.3-V LVTTL level logic thresholds.
The active-high enable input (ENA) pin is used to turn-on the isolated DC/DC converter of the module. Either 3.3-V or 5-V logic rails can be used. Maintain the ENA pin voltage below 5.5 V.
The active-low powergood (/PG) pin is an open-drain output that indicates (low) when the module has no fault and the output voltages are within ±10% of the output voltage regulation setpoints. Connect a pull-up resistor (> 1 kΏ) from /PG pin to either a 5-V or 3.3-V logic rail. Maintain the /PG pin voltage below 5.5 V.