STM32H745 - USB power pins - connect to VDD or Open

Joe.H · ‎2022-01-13

If you are NOT using USB with the STMH745 - what is best practice - Connect both the 5 and 3.3 USB power pins to 3.3v or leave them unconnected?

Peter BENSCH · ‎2022-01-14

Well, the datasheet of the STM32H745 as an important reference only specifies how to connect VDD33USB:

All main power (VDD, VDDA, VDD33USB, VDDSMPS, VBAT) and ground (VSS, VSSA) pins must always be connected to the external power supply, in the permitted range.

and additionally in table 23:

USB not used: VDD33USB = 0...3.6V

I'd recommend: connect VDD33USB to GND (saves some supply current), leave VDD50USB unconnected and make sure that the VDD33USB supply level detector is disabled.

Regards

/Peter

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Peter BENSCH · ‎2022-02-17

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/Peter

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