AltairClone wrote:Yes - good looking scope shots and it sounds like you have your head wrapped around the issue.
The minimum phi2 high time is 220ns, so I don't like to take all the time we need from phi2 - that leaves us too close to the 220ns parameter.
The minimum phi1 high time 70ns, so we can take some time from there as well, which adds to the time between phi2 fall and phi1 rise that we need.
Assuming R42 for phi2 is presently 6.2K, then 5.6K will take you from 280ns on phi2 down to around 250ns. That gets us about 30ns
Assuming R41 for phi1 is presently 13K, then 10K will take you from 125ns on phi1 down to around 95ns. This gets us another 30ns. This give us 60ns total additional time between phi2 fall and phi1 rise.
Mike
Thanks Mike, this should be a pretty straight forward mod. I'll head to the store tomorrow and get the required resistors.