The data sheet doesn't include any requirements on the 32.768 xtal. Can ADI recommend a specific part? Or provide guidance on allowable ESR for the xtal?
The purpose of Engineer Zone is to provide communities for the support of select Analog Devices products. We are not allowed to recommend parts from the other manufacturer. The AD7709 is intended for use with a 32.768KHzwatch crystals. The absolute accuracy and temperature drift of the clock source is important. In some cases, it will be necessary to connect capacitors on the crystal or resonator to ensure that it does not oscillate at overtones of its fundamental operating frequency. The values of capacitors will vary depending on manufacturer specifications.