SC16IS752IPW Reset

[Pudl]

Hello together,

I use the SC16IS752IPW 16 times on a big PCB.

Since I made a new revision of the PCB the SC16IS752IPW allways looses its setting (makes a reset) after switching a relais near the chip. The astonishing thing is, that between the revision bevor and the actual one I din't change anything around the Relais or the  SC16IS752IPW.

Measuring the souroundings of the chip I get a ripple at the 3.3V supply voltage (400mVpp for 1us) at the Reset input (1Vpp for 100ns) and at the I²S Data/Clock (1Vpp for 100ns) while switching the Reliais. Can this be the reason for the reset of the chip?

Best regards

Michael Pfab

[reyes]

Hi Michael Pfab,

Yes, I do believe that the cause of the reset you are seen is the ripple you are seen at the Reset input.

Suggest you to add a decoupling capacitor on this rail to try to reduce the ripple.

Have a great day,
Jose

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