The PPD pin can be used to override the internal hotswap MOSFET UVLO (VUVLO_R and VUVLO_H) when using low voltage adapters connected between VDD and VSS. The PPD pin has an internal 5-μA pulldown current source. As an example, consider the choice of RPPD1 and RPPD2, for a 24-V adapter.
The PPD pin can also be used to modify the internal MOSFET UVLO for use with a lower output voltage PSE (within certain limits). Connect the RPPD1 and RPPD2 dividers directly between VDD and VSS with the midpoint connected to PPD. For this case and to allow classification, target the minimum PSE OFF voltage (VADPTR_OFF) > VCU_OFF = 23 V. Then follow the procedure outlined above to select RPPD1, RPPD2, and determine the PSE ON (VADPTR_ON) and PSE OFF (VADPTR_OFF) voltages ensuring that PSE OFF > 23 V. Lastly, because the RPPD1 and RPPD2 divider is in parallel with RDEN during detection, RDEN must be increased such that the equivalent detection resistance is 25 kΩ nominal.