I built a special kind of controller that uses seven MCU's working in parallel, and I'm quite pleased with the result. The arrangement works using a single oscillator whose output is connected in series to each MCU, and so far things are working nicely. The thing's supposed to generate a 0-5V 14.7456 MHz square wave, but I was surprised to see a horrible amount of under and overshoot when I scoped it.
The components are arranged so that the oscillator is installed on one side, and then a single line is connected sequentially to each MCU, which are separated about 2-1/4" inches from each other. That is, the total trace length from the oscillator to the last MCU is about 15-1/2". And that is a looooong trace to be used for this purpose, I know.
I'm guessing this dirty reading might be due to one of two reasons:
Any suggestions on how I might clean that signal a bit, making it more square-like? ... other than redesigning the entire PCB, of course... Or is it a non-issue, since it's working fine anyway?
The components are arranged so that the oscillator is installed on one side, and then a single line is connected sequentially to each MCU, which are separated about 2-1/4" inches from each other. That is, the total trace length from the oscillator to the last MCU is about 15-1/2". And that is a looooong trace to be used for this purpose, I know.
I'm guessing this dirty reading might be due to one of two reasons:
1.- My scope sucks. It's a humble digital hantek dso-2250 usb 100 MHz scope.
2.- The long trace is causing an inductive load with the above results.
2.- The long trace is causing an inductive load with the above results.
Any suggestions on how I might clean that signal a bit, making it more square-like? ... other than redesigning the entire PCB, of course... Or is it a non-issue, since it's working fine anyway?
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