Other Parts Discussed in Thread: NE5532
Hello,
I am using a Birt differential circuit in front of the CPM1863 and thus have a good location to inject a CM voltage. This would remove the need to AC couple my signal twice which has benefits.
I observing that the bias voltage on the ADC inputs is the same voltage as VRef. And i was considering supplying Vref as a bias voltage into my Birt Differential receiver; however, section 9.3.1 of the data sheet recommends against this, but does not consider the use case injecting the CM voltage externally.
Using NE5532's with a max input offset voltage of 5mV, and a series resistance of 100Ω between NE5532 output and ADC input, there is a maximum 50µA push pull between the two devices. Not sure if this is problematic.
The Typical offset voltage of 0.5mV gives potential 5µA current load.
- Adam