Hi,
I haven't tested the current draw from USB port, but the unit wasn't drawing much current when initially connected to power supply. Even after enabling basic functionalities like LEDs, the current draw was as high as 0.02 A for a while. If I remember the figures right, V_USB, D_N and D_P pins had voltages as high as 4.8 V. How could this affect USB though? Could you elaborate please?
However, that's a good point you raised. Initially, the board was drawing 0.01 to 0.02 A. However, after a while even though only MCU is operational, the current draw was going as high as 0.06 A. This happened after I started experimenting with some pin connections and was driving them externally. Could that be due to a damaged pin on MK20 leaking current? Or is it another problem?