jutek
Full Member level 4
capacity discharge
hello
The picture presents capacity discharging process. It takes more than 5us and it's related to time constant 1uF and about 6ohm.
i need something to discharge it faster without changing capacity and resistance.
It should take less than 1us.
I thought about shortcut which will short capacitor to ground just after discharging starts and stop when it discharge.
I want to use a big nmos key which will be driven by comparator.
Comparator checks the moment when discharging begins and then turns on the transistor key.
I have checked this solution, it almost works but..
The comparator is too slow. It's rising and falling time are too long cause it drives big transistor key (W=8m).
I have used 2 cmos buffers to sharpen comparator's output, but strange voltage peaks appear.
I'm limited by low current (10u) so i can't increase comparator's bias current.
How can i make it faster or can you suggest another possible solution?
regards
hello
The picture presents capacity discharging process. It takes more than 5us and it's related to time constant 1uF and about 6ohm.
i need something to discharge it faster without changing capacity and resistance.
It should take less than 1us.
I thought about shortcut which will short capacitor to ground just after discharging starts and stop when it discharge.
I want to use a big nmos key which will be driven by comparator.
Comparator checks the moment when discharging begins and then turns on the transistor key.
I have checked this solution, it almost works but..
The comparator is too slow. It's rising and falling time are too long cause it drives big transistor key (W=8m).
I have used 2 cmos buffers to sharpen comparator's output, but strange voltage peaks appear.
I'm limited by low current (10u) so i can't increase comparator's bias current.
How can i make it faster or can you suggest another possible solution?
regards
