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USB / Re: Transition from HS to FS USB
« on: March 11, 2022, 07:46:15 PM »
In order to have some sort of conclusion on this. After reducing the Kinetis flash clock to 20MHz (from 24Mhz, confirmed using an oscilloscope), the hard fault disappeared. After further investigation into another issue (noisy ADC readings) we believe the problem is actually the design of the chip's power supply lines. Instead of a 3V3 plane with decoupling capacitors close to the pins themselves, our design has a single trace running from all the 5 supply pins to the outside of the chip and then the decoupling capacitors are all placed in parallel there.
We're currently doing another design iteration to confirm that was indeed the problem. Will update this post when that happens. Thanks for your help!
We're currently doing another design iteration to confirm that was indeed the problem. Will update this post when that happens. Thanks for your help!