I am facing a problem when trying to use the AD7992. I have a Linux based Board which I am using for development of different sensor systems. The board has been extended by using a PCA9544A Multiplexer (4-Channel) to have 4 I2C-Busses. I am successfully using those busses to read different sensors/ICs e.g. AD7746. A very helpful function to detect I2C-devices in Linux the use of i2cdetect from the the i2ctools package. Every other I2C-device I connect to one of the multiplexer busses is detected right away and simple read/write operations are easily possible. Now I have tried to connect the AD7992 however even with the most basic circuit I cannot detect the device. My"basic circuit" looks like this:
1: CONVST: floating
2, 7: Ground of analog device
3: 5V power supply
4: reference voltage from a voltage source
Any ideas what the problem could be? Your help is very much appreciated!!!