I have three AD7607 to get 24 analog inputs.
Unfortunately the number of my µC-I/O-pins is limited.
Can I parallel the control pins of the ADCs to free some µC-I/O-pins,
or acts the /CS only on the ADC-databus?
You may use multiple AD7607 using with your microcontroller but there are ADC pins that can be shared and there are others that need to have separate. Like the CS, this signal frames the data of the ADC, to frame the data of the specific ADC, only the CS of that particular ADC should be pulled low. There is an ADI circuit note available that you can refer to for your reference. The circuit note use the AD7606 which is co family of AD7607. You may refer to the link of CN0148.
It is obvious to separate the /CS of the ADCs to read the data bus separately.
Meanwhile I decided to parallel the inputs of the ADCs (Convst, /RD, Reset) but to keep separate the outputs like busy and Frstdata.
In the application note CN0148 only the busy of U1 is connected to the interface, probably assuming that U2 has completed the conversion too, when U1 has.
I don't know whether this is allowed or good design practice but certainly should work if the ADC-conversion-times are equal.
The BUSY1 which is the busy for U2 is connected to the J1-A11 of the CED controller board where the CN0148. The BUSY for U1 and U2 where separated. The read operation for each AD7607 can be separated.
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