If 3.3V is applied to D+ (or D-) without supplying power to VCC (VCC_D/VCC_A), will the device be damaged?

[SuSh_1535366]

Hello,

If 3.3V is applied to D+ (or D-) without supplying power to VCC (VCC_D/VCC_A), will the device be damaged?

Please tell me about the downstream and upstream ports respectively.

Regards,

Shimamura

[MallikaK_22 · Accepted solution]

Hi Shimamura,

As you might be knowing, D+ is pulled up to 3.3V. As per USB spec, the voltage source on the pull-up resistor must be derived from or controlled by the power supplied on the USB cable such that when VBUS is removed, the pull-up resistor does not supply current on the data line to which it is attached. So, in absence of VBUS 9VCC), there shouldn't be current on the data lines.

Regards,

Mallika