I've built a PCB using the below circuit. I'm having some issues when the solenoid is being energized. It seems as if the kickback is getting into the ground plane affecting the PWM signal. Any help/tips on how to clean up this noise will be appreciated.
The solenoid current is about 1.3Amps for first 10ms @ 90% duty cycle then duty cycle drops to 50% for remainder of actuation. Frequency is set at 24Khz.
EDIT 2: Added a gate resistor (divider R29,R30) at output of U2. Seems to have reduced the noise issue.
Ch1 on the scope (green) is looking at the voltage across the solenoid connected at J2. Ch2 on the scope (yellow) is looking at the PWM_ON signal coming from the micro at R2. I've added a resistor divider and seems to have helped a little, but still very crappy.
Also maybe Q1 is not fully turning on?