AD7689

Hi everyone,

i have a problem with the AD-Converter AD7689.

As long the temperature of the device/board is below +50°C all nine channels are converted correctly.

If the temperature rises, i see a shift of the channels. It seems that one or more channels aren`t converted and so the sequence of the channels is mixed up.

When the temperature goes back below 50°C, the effect disappears.

We use an external reference voltage of 5V and an IO-Supply of 3V3. And they don't show any abnormality.

The internal temperature sensor isn't available in this configuration. So we use his dummy value as an reference point to detect and repair  the shifting.

Does anyone have a clue for the behavior?

Regards,

Ralf