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ADS7229 Input leakage current

Weixi FENG
Prodigy 30 points

I'm a university student doing a mini project on ADCs. Could someone please explain what is input leakage current in the datasheet? Does it refer to the current draw from analog input?

  • 0
    TI__Expert 3785 points

    Hi Weixi,

    Depending on which ADC you are using, the front-end circuit of the ADC will draw some current from the source even when it is not converting. This is the leakage current specification.
    Usually the leakage current in the analog input pins will be less than 1uA. This information is useful in determining if you could directly interface a sensor to the ADC.

    However, an ADC with a sample-and-hold circuit will have sudden burst of charge drawn from inputs when the sampling switch is closed. This is called 'kick-back'. This effect is not covered by the analog input leakage specification.

    Going by the ADC architecture you chose to use, you could decide how to interface your signal to the ADC.

    I hope this answers your question.

    Regards,
    Rahul