SLVSF02D March 2019 – May 2020 TPS23881
The recommended VDD supply voltage requirement is 3.3 V, ±0.3 V. The TPS23881 requires approximately 6 mA typical and 12 mA maximum from the VDD supply. The VDD supply can be generated from VPWR with a buck-type regulator (A LM5017 based device is recommended) for a higher port count PSE using multiple TPS23881 devices operating in semiauto mode. The power supply design must ensure the VDD rail rises monotonically through the VDD UVLO thresholds without any droop under the UVLO_fall threshold as the loads are turned on. This is accomplished with proper bulk capacitance across the VDD rail for the expected load current steps over worst case design corners. Furthermore, the combination of decoupling capacitance and bulk storage capacitance must hold the VDD rail above the UVLO_fall threshold during any expected transient outages once power is applied.