Op Amp speed in Analog Diode Drivers

[wolfblue]

If i wanted to build mosfet diode drivers for a projector to run at 30k( or more), how fast would the op amps need to be?

Seems like a LM6132 would be good. Rail to Rail at 12v/μs and 10Mhz GBW. And you can get them in DIP. Surface mount is kind of too small for me.


--John

[mixedgas]

[QUOTE=wolfblue;98824]If i wanted to build mosfet diode drivers for a projector to run at 30k( or more), how fast would the op amps need to be?
endeth quote

Seems like a LM6132 would be good. Rail to Rail at 12v/μs and 10Mhz GBW. And you can get them in DIP. Surface mount is kind of too small for me.

10 mhz gbw sounds fine, keep in mind that high gains in circuit slow the opamp down, but 10 mhz is more then enough. Ie 1 megohm of feedback is much slower then 10K. To a point.

[LesioQ]

For quite a time I was tempted to build an analog LD driver with low side mosfet using LT1575 IC. It's fast, handles mosfet input capacitance, and is dip .
Piotr.K

[wolfblue]

Thanks for the input guys

1 megohm of feedback is much slower then 10K.

I'm just a electronics hobbyist. But I don't think I ever used big resistors in op amp circuits. And I am more comfortable with low gain. I've used op amps for various things for years. And they work as advertised they way I been using them. With low gain and just enough resistance to keep the current down. Maybe the data sheet charts have made me think they work better at lower gain. But thats a good point you mad Steve. Thanks.

T1575 IC. It's fast, handles mosfet input capacitance, and is dip .
Piotr.K

Thanks for showing that chip. I thought about it for a few days, and I can't really decide. I may actually go that route. Or I may still go with the op amps. I cant decide

But I need five analog drivers. I would like to save time and use the new flexmod. But I am better off to save money.


--John