ADS4225: Negative voltage -0.6V on INx pins

Yusuke Mukuno

Part Number: ADS4225

Hi Expert,

Customer found the negative voltage -0.6V on INx pins during startup transient.

It is over absolute maximum voltage(-0.3V). Is there the diode between INx pins and GND?

The input pin has a 100ohm series resister to limit input current.

Will this negative voltage have any risk?

Thanks

Muk

jim s over 3 years ago

Muk,

There is a diode but I am not sure how low the input can go before damage may occur. I am checking with the design team regarding this.

Regards,

Jim

Yusuke Mukuno over 3 years ago in reply to jim s

Hi Jim-san

Do you have any update from design team?

Thanks

Muk

jim s over 3 years ago in reply to Yusuke Mukuno

Muk,

We do not think this will be an issue if your circuit looks like the one attached.

The forward bias current through diode (assuming 0.3V cut off voltage) is limited to 30mA.

Regards,

Jim

Yusuke Mukuno over 3 years ago in reply to jim s

Thanks Jim-san!

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