I'm searching for an optimized 4 channel op amp to drive a 4 parallel mosfets for an electronic load. I'm able to achieve ~0.02A/uSwith an AD8630 by using a 330R resistor to gate or about 15mA per channel. The AD8630 has an output short circuit current of 50mA, so I'm a bit overspec, but its stable. I need more power!
The AD8534 says it has a "250mA Output". Then I realized I didn't actually understand if the datasheet specification for "Output Current Limit", "Output Short Circuit Limit", etc, was for the entire device or per channel. I figured these specs were for the entire device regardless of if its a single or quad channel amp. But I really don't know!
I'm using the same mosfets as the Rigol Electronic load, and it has a claimed spec of 5A/uS with 12 Fets. I think it has a 3.3R resistor and when you do the math with the gate charge its in the ball park of 5A/us. How does one deliver 4Amps to a mosfet gate in the linear region in a controlled manner? I mean you can use a gate driver, but that's just for slamming the gate open and shut.