SLVS933D July 2009 – December 2020 TPS23753A
The MPS is an electrical signature presented by the PD to assure the PSE that it is still present after operating voltage is applied. A valid MPS consists of a minimum DC current of 10 mA (at a duty cycle of at least 75 ms on every 225 ms) and an AC impedance lower than 26.25 kΩ in parallel with 0.05 μF. The AC impedance is usually accomplished by the minimum CIN requirement of 5 μF. When APD or DEN are used to force the hotswap switch off, the DC MPS is not met. A PSE that monitors the DC MPS will remove power from the PD when this occurs. A PSE that monitors only the AC MPS may remove power from the PD.