I have designed a base board for OVERO FIRE COM which supports USB battery charging. When USB cable is connected but no other power is applied, there is ~0.9V on VSYSTEM pins from COM. Here only power applied to COM is VBUS from USB which goes to PMIC on COM.
What can be the reason for this? I think that it is through PMIC that ~0.9 is coming on VSYSTEM. Is there any way to resolve it?