I want to move the low side enable switch of my H-bridge onto the high side, because for safety reasons it's better to turn off the tap than plug the drain. I'm powering a 24V, 35W BLDC, so it's nothing too serious. Rather than adding a 36V supply to my board only to drive a high side NFET, I decided to go with a PFET, however its logic is inverted, and I want the H bridge to turn off in the event the enable line de-energizes. That way, it fails safely.
This is the design I came up with:
The transistor is by default off unless an enable signal is applied to Q2. If Enable should droop or get disconnected, the H bridge will be disabled.
The issue is that since the H-bridge will be on most of the time, there will be a current through R1 to ground. Since I don't want to waste my battery, is there any way I can pick a large R1 to minimize that current, without trashing the gate drive of Q1?