Detect device type. ADAU1966 or ADAU1966A

Question

Hi 
 I wonder if someone could help me with this. 
 Is there a way to detect whether ADAU1966 or ADAU1966A is fitted to a board via I2C? 
 I work on equipment that uses multiple ADAU1966 DACs. 1 on a main board and 2 on a separate board sharing the i2C bus. So it's possible we may end up with a mixture of ADAU1966 and ADAU1966A working together. 
 This IC has now gone obsolete and is being replaced with 3.3V compatible alternative, ADAU1966A . I've been testing the ADAU1966A and I'm getting a 0.66 lower output from the DACs for the same input. I assume it's because the internal voltage reference is 1.5V rather than 2.25V as before. 
 So I need to be able to detect, which IC is fitted so we can adjust the output amplitude in the software. I thought there might be register for the device ID or version that could be read, but so far I can not see one. 
 Thanks and kind regards

DaveThib · Accepted Answer

Hello sherlock1, 
 
 Unfortunately, we did too good of a job making these two parts drop-in replacements from a software control basis. There is no register to tell the difference. My suggestion is to have some sort of GPIO going to a pin on the board that is tied high or low. 
 FYI, you can set the CM voltage reference to be 1.5V on the ADAU1966. This would make the output of the ADAU1966 match the ADAU1966A. But there is no way to bring the "A" version parts up to 2.5V. That register is internally tied to the 1.5V setting so the register value is ignored and is only there for software compatibility. 
 Dave T)

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Detect device type. ADAU1966 or ADAU1966A

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