Hi
Our customer are considering the damping resistor. If the Pin#4(output of channel 2) is connected to Pin#1(input of channel 1), should we add the dumping resistor between Pin#4 and Pin#1?
I think the pattern trace is very short and does not need. (signal freq:120kHz. the trace is connected as possible as short.)
Regards,
Koji Hamamoto
Hi Hamamoto-san,
What you have described is the correct way to add a damping resistor.
Typically, a damping resistor is added to reduce reflections due to impedance mismatches, but in the case you have described, the ringing is more likely caused by the light load and some parasitics. The two cases are shown below:
It seems unusual for there to be excessive ringing when connecting two channels of the same device in series. Can you tell me more about the application?
