About KMach.1

KMach.1 · 2021-04-15

I have the same problem as described and unanswered here: https://community.st.com/s/question/0D53W00000IUzefSAD/nucleo-h745ziq-drawing-current-spikes-from-usb-power-port-producing-noisy-5v i.e. bursts of current spikes each 18 ms.The particular boar...

KMach.1 · 2021-04-15

It is the Ethernet PHY, it is active even without any MAC running in the MCU. To disable it, you need to remove SB177 and tie the concave pad to ground.

KMach.1 · 2021-04-15

Okay, now I feel dumb. It was all caused by the Ethernet PHY which I thought was disabled. But to keep it resetted one has to remove SB177 and add a bodge wire to GND.

KMach.1 · 2021-04-15

Yes, the disturbance on VCAP (and everywhere else) is synchronous with the current spikes. The unsettling thing is the perfect regularity of the noise. When i set the scope to normal mode with 5 ms holdoff, the waveform can be zoomed and panned with ...

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Nucleo H743, large spikes in Idd in regular pattern

Re: Nucleo H745ZI-Q drawing current spikes from USB power port - producing noisy 5V

Re: Nucleo H743, large spikes in Idd in regular pattern

Re: Nucleo H743, large spikes in Idd in regular pattern