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ADS8883: What is maximum input current through ESD diodes and maximum input voltages under continuous out of the normal input voltage range

Part Number: ADS8883
Other Parts Discussed in Thread: ADS8881, , ADS8885, ADS8887, ADS8860

What is the maximum input current through the ESD input protection diodes?  What would be a safe value for continuous situation?

Note:  "ADS888x", I mean ADS8881, ADS8883, ADS8885 or ADS8887. 

Went through this guide (at the link below) and it indicates a maximum input current of +/-15mA for the ADS8860. Would this be same for the differential inputs of the ADS888x?  

Is there an aggregate max current, if both the positive and negative input voltages were exceeded?

Circuit for protecting low-voltage SAR ADC from electrical overstress with minimal impact on performance

Further, is it the case that the input voltage must be limited as well?  In other words, limiting the input current is not enough for adequate protection?

Thanks,

Mike

  • Hello Mike,

    Thank you for your post.

    The ESD diodes are there for momentary ESD event protection and should not be relied upon for protection from continuous or sustained overvoltage events. I do believe they are similar, if not identical, between all devices in the ADS88xx family of SAR ADCs. External protection circuitry should be designed such that the voltage is limited to within the Absolute Maximum Ratings specifications and the internal ESD diodes do not have to turn on.

    Regards,

    Ryan