Hi All,
I'm new to the AMC6821, and am using the AMC6821EVM-PDK kit to evaluate it.
I have a problem where I can't get the PWM signal to change at all. The o-scope shows it's high all the time, with no pulses. I've tried several of the automatic loads in the VI software tool, and the fan rpm never changes from full rated speed - as verified by the tach signal.
I can update/change duty cycle registers in the VI tool, but the actual signal to the fan never changes.
I have verified that the fan responds correctly to a PWM signal from an function generator when the EVM is not in the loop.
I've looked at the HW jumpers and think everything is setup per the manual. I'm now at the point where I don't know what to check next.
Any suggestions would be appreciated.
Thanks,
Michael