I'm designing an H-bridge to power a linear actuator to extend and retract. The actuator will be driven by a 12V supply, but board logic will probably be 3.3V. This will be a very slow mechanism and it won't be driven back and forth quickly (read: shoot-through in the H-bridge is not an issue).
For simplicity, I'd like to use two low-side N-channel FETs and two high-side P-channel FETs. But, of course, I can't drive the P-Channel directly from the 3.3V logic on a 12V system. So, I'd put pull-up resistors on the gates of the P-Channels to keep them off. The DIO pins connected to the gate pins would be kept in high-impedance state. When I wanted to turn on one of the P-Channel FETs, I'd just change the DIO pin to an output at 0V. And back again to high-impedance to turn the FET off. The N-channel FETs would have logic level gates and be driven directly from a DIO pin.
Any reason this wouldn't be a robust design? In the past, I've made H-bridges using ICs made for the purpose, but those were for systems that switched back and forth quickly and had high chance of shoot-through. This actuator will be slowly extended, turned off for a while, and then slowly retracted later.
Thanks!
For simplicity, I'd like to use two low-side N-channel FETs and two high-side P-channel FETs. But, of course, I can't drive the P-Channel directly from the 3.3V logic on a 12V system. So, I'd put pull-up resistors on the gates of the P-Channels to keep them off. The DIO pins connected to the gate pins would be kept in high-impedance state. When I wanted to turn on one of the P-Channel FETs, I'd just change the DIO pin to an output at 0V. And back again to high-impedance to turn the FET off. The N-channel FETs would have logic level gates and be driven directly from a DIO pin.
Any reason this wouldn't be a robust design? In the past, I've made H-bridges using ICs made for the purpose, but those were for systems that switched back and forth quickly and had high chance of shoot-through. This actuator will be slowly extended, turned off for a while, and then slowly retracted later.
Thanks!