Drive DC Motor with H Bridge(H Bridge turns off too slow and problem with current monitor)
To switch a power MOSFET, you have to move a substantial charge through the gate and the source. The datasheet will specify something like "total gate charge". In order to move all that charge in a short time, you need high current. And in your circuit you can't have high current, since the current through the gate is ultimately limited by R1 and R3.

In other words, the problem is that with your design, U1B does not fully turn off until some time after S1 goes low. And when it does turn off, it does so slowly, which is why you see the voltage at T1 ramp down slowly. See What is MOSFET gate drive capability and why do I care about it?

In order to reduce this problem, you need to increase the current that your gate driver can source and sink. A simplistic solution is to add a pair of emitter-followers, like this:







simulate this circuit &ndash; Schematic created using CircuitLab

You can get fancier with a discrete approach like the one that follows. In addition to having emitter followers to increase the current drive, it uses a clamp (D13, D23) to reduce the storage delay of the BJTs Q11 and Q21. You can read more about it in another answer.



Or, you can just buy an integrated MOSFET gate driver and call it a day.