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AD7192 source impedance

Question asked by Bert on Apr 6, 2011
Latest reply on Apr 7, 2011 by MMA

The datasheet of the AD7192 states that you could use the inputs both buffered as unbuffered.

As I have a sensor (which will be used in a quarter wheatstone bridge configuration) with a nominal resistance of several kOhm (could be 30 kOhm) I was wondering if the buffered mode would be enough to keep a good resolution.

 

The datasheet mentions that a value of 1.4 kOhm can be reached in unbuffered mode, but I'm not sure which range can be reached in buffered mode.

 

Currently I'm using an AD624 instrumentation amplifier followed by an ADC interface but I'm searching for a single chip solution with digital programmable configuration. Is it possible to interface sensors of several kOhms with the AD7192 set in buffered mode or should I add an external high impedance buffer myself and use the AD7192 in unbuffered mode?

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