Opamp selection

Hi sahard

Checking on Analog Devices’ portfolio you could look at ADA4096-4. ADA4096-4 meets most of your requirement, it is capable of +/-3V dual supply operation with a supply current of 65uA per amplifier. Its offset voltage is also relatively small with a typical value of 35uV. Your requirement of 4 circuits, which I think you refer to as 4 amplifiers in package, is also met by ADA4096-4 along with the package requirement of 16-LFCSP. It does not reach your requirement, though, of 2V/us Slew Rate, it can only provide up to 0.25 V/us Slew Rate.

Often there is a tradeoff between slew rate and current. For faster devices, you would expect the part to draw more current. Why do you require a high slew rate? What will the current source be driving? If you really need a high slew rate in your application, you could also check AD8643 which reaches your Slew Rate requirement of 2V/us, its offset voltage is 50uV but the supply current is much higher at 195uA per amplifier. Could you provide more details about your application? With more information, I could provide a better part for you.

Thanks

Chard

It is a variable current source. For example, if the load is 50kohm, the output current I produce will not exceed 60ua.

Hi chard,

Thank you for finding these opamps for me.

The reason I would like a fast opamp is because I am generating current pulses used for neuro-stimulation. I would like the pulses to have a risetime of <10us. If I draw a maximum of 100uA across a 30kohm resistor, then the opamp should have at least a slew rate of 0.3V/us to meet specs. Looking at the options you provided in your first paragraph, 0.25V/us is a good option if that is the best we can do.

I also, would like a low current consumption opamp because the device is battery operated, so it must have a low supply current of <100uA.

Best,

Sara