For low power application that requires RRIO and greater than 5V supply, I would recommend the AD8657 due to its low supply current of 22 uA per amplifier. The AD8657 is a 18V, micropower, rail-to-rail RRIO amplifier optimized for low power and wide operating supply voltage range. To address your design challenge, we have a tested circuit design specific for this application, please refer to CN0179.
For low cost applications, I would recommend the AD8546, due to its low supply current of 33 uA/ amplifier over temperature and supply voltage.
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