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ADUM141ES Output Impedance

Thread Summary

The user is experiencing non-monotonic signals at the receiving circuit when using an ADuM141ES at 5V. The output stage is push-pull CMOS and not designed to drive a 50Ω load, potentially violating the ±10mA output current limit. The output impedance is in the 60-80Ω range, and the issue does not occur at 3.3V with a 33.2Ω source termination. The user is advised to contact technical support for further assistance.
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Category: Hardware
Product Number: ADUM141ES

Is there any information available about the output impedance of the VOA, VOB, VOC and VOD outputs? I would like to best match the output impedance to the trace transmission line impedance. I tried to ask this same question on an older thread over a month ago, but got no replies.

Ideally, I'd like to have an IBIS model, but the output impedance will do for now.

 

For reference, we are seeing what appears to be a non-monotonic signal at the receiving circuit (high impedance digital input) of a signal that originates from an ADuM141ES operating at 5V. We have a source series termination resistor and the trace between the ADuM141ES output and the receiving circuit is designed with a 50Ω impedance. We've varied the source termination resistor and have not been able to remove the non-monotonicity. We've also wired in a parallel load termination resistance of 680Ω and that also has not helped.