I am seeing the 8801 drop out when driving the enable line with PWM. I have tried 5 KHz and 10 KHz. Similar behavior.
Both runs: Phase 1, Mode(1,2) 0, nSleep 1
Runa111: 
5 KHz PWM of enable, 90% duty for boost, 30% for hold current.
Purple: coil voltage
Blue: enable PWM
Yellow: coil current
Runa112 : 10 KHz PWM of enable, 100% duty for boost, 30% duty for hold current
Purple: coil voltage
Green: nFault
Blue: enable PWM
Yellow: coil current.
Please let us know your thoughts.
Wilson,
We need you to take another look at this. It seems that even when we hold ENABLE high, it will only keep the top FET on for about 5ms. and then it will cycle at 5ms on and 5ms off. You will also notice, then even when we transition ENABLE from low to high, the top FET will not always come on right away. Seems like if it is in the 5ms dead zone, then it won't come on ?????
We tried just a resistive load to simplify the situation.
What do you suggest??
Thanks
Setup:
Load = 8.5 Ohm
Vbat = 12 Volts
Coil drive = 15 Hz PWM @ 50% modulation
(Files: EN, SENSE, VCP, Output Voltage 8.5 ohm Load.jpg and EN, SENSE, VCP, Output Current, 8.5 ohm loadjpg.jpg)
