I am trying to use the UCC27210 to drive mosfets for a high power regenerative solenoid driver.
The solenoid is between the high and low side mosfets, with flyback diodes to allow for the regenerative mode.
In all other respects the mosfets are being driven exactly as per the typical application in the data sheet.
The normal operation mode is to switch both mosfets on, then pwm control the high side mosfet until the end of operation, then turn both high and low side mosfets off.
The problem is that the high side mosfet is only being turned on once at the start of the pwm section - see HO in logic diagram. The logic waveform is present and correct at the HI input of the UCC27210, but not the output. I have to turn the low side mosfet off, before the high side mosfet output HO can be turned on again.
Scoping around the device does not lead me to believe that the under voltage lock out mode should be getting invoked - the voltage Hb-Hs is maintained throughout the operating period.
Does anyone have any idea why this is happening? and what I can do about it?
Thanks
Ian
