What is the effective PD load-resistance corresponding to 10 mA at, say 50 V? It is *V*/*I* = 50/0.01 = 5 kΩ. The wattage is *V* × *I* = 50 V × 0.01 A = 0.5 W. If the output of the PD was 12 V, then assuming 100 percent efficiency for the DC-DC converter, we need to preload the PD for 0.5 W minimum load. That leads to a preload resistor of *V*^{2}/W = 12 *V*^{2}/0.5 W = 288 Ω. So we can provide the MPS by connecting a 5-k resistor directly across the port, but that would obviously interfere with detection and classification. So the correct option is to include a resistor of less than 288 Ω across the 12-V output rails.

If the efficiency of the DC-DC stage is, say, 80 percent, then the output power corresponding to 0.5 W at the input is 0.5 W × ...

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