I have a n channel MOSFET controlling a high current LED panel. The FET is driven by a FET driver, which is itself driven by a MCU pin. I am using PWM to control the LED brightness.
I want to double check the PWM with my scope, to ensure the duty cycle is correct. I can check all along the circuit, and I get proper readings from my scope. If I check the outputs from my FET, I get a garbage reading.
This is because, I believe, when the FET is off, the ground clip is disconnected from the ground reference, and it is left floating.
How can I check the FET output with my scope, since whenever the pulse is low, the ground reference is no longer connected?
EDIT: PWM should be 0-12vdc square wave, 5khz, 10% duty cycle. Also, when I use with the LED, it dims properly as would be expected with PWM, so I'm almost positive it is outputting correctly.