Self powered device

user_1245661 · ‎Mar 20, 2019

Hello Sir,

I'm developing a self powered device, I have connected the FX3 VBUS pin at the USB 5V pin and the other voltages (VDD, VIO, ecc...) are supplied by an external power supply unit.

What happens if the external power supply stays off and the device remains connected to the PC? I assume that only the PHY module remains powered while the rest of the chip will be turned off.

Is this situation dangerous for the FX3? Is there a risk of damaging something?

Thanks in advance.

Regards

Nick

alamandaa_16 · ‎Mar 20, 2019

Hi Nick,

I think FX3 Power supply domains are supplied by an external power supply, is it right?If yes, in that case you are right.

What happens if the external power supply stays off and the device remains connected to the PC?

only the PHY block is active and rest of the chip should be turned off.

Is this situation dangerous for the FX3?

Nothing has happend for the FX3.

Regards,

Anil Srinivas.

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Self powered device

Self powered device

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