Reset issue STSPIN32F0A

[CCarl]

Hello,

I have some troubles with the STSPIN32F0A when the load on the motor increases,

the STSPIN will reset.

The reset cause is checked in firmware at startup, and the cause mentioned is RCC_FLAG_PINRST.

Apart from a pull-up and a capacitor to ground, there is no hardware on the reset pin.

The voltage on the VDDA, VDD and VREG pin are correct at the time of reset.

What could be the cause of this reset?

Thanks.

Joris

[GMA]

Hello @CCarl,

Are you using STEVAL-SPIN3202 board or a custom board?
Did you check with a scope the NRST input signal?

[CCarl]

Hello GMA,

I am using STEVAL-SPIN3202 board.

I checked NRST signal with scope and without jumper2,

I see the NRST level is going below 2.8V when the load on the motor increases.

That is when the STSPIN32F0A is reset.

[GMA]

Hello @CCarl,

On your previous message, you mentioned that VDD was correct but as NRST is linked to VDD (see page2 of steval-spin3202), you should also see a drop on VDD, isn't it?! 
VDD comes from VM input via "DC/DC buck conv" feature (see stspin32f0a), could you please also check your DC supply value? DC supply current limitation could be the voltage drop root cause for example.

[CCarl]

Hello GMA,

There is no drop visible on the VDD signal.

It is like the STSPIN32F0A is pulling his NRST line low for some reason.

[GMA]

Hello @CCarl,

Is-it possible to replace the reset filtering capacitor C6 on your board from 3.3nF to 100nF?