gain of ad620

my input is a 40khz pwm .

acc. to fig17 in the datasheet the voltage gain is 200 . does that mean i can not get higher gain with any resistor I attach to adjust gain?

There are lots of versions of the datasheet - provide a link to the one you are
talking about please since figure 17 isn't the same...

Gain set with one external resistor
(Gain range 1 to 10,000)

Looking at the data sheet, the maximum gain is 1000 so it depends on the external resistance you are using. Also, the affects the maximum frequency you can use. At a gain of 1000, the bandwidth is less than 10KHz.

Also, this is an instrumentation amplifier, the input is designed for differential input signals. Watch the grounds.

Do you need a close to square wave at 40KHz? What are you using it for?

Hi, to answer your question, yes 200 at 40kHz is the maximum, the GBWP comes into effect.
(WOW University Electronics lesson Flashback)

Tom..... :slight_smile:

Instrumentation amps are designed for essentially DC measurements, this is not the right device
for 40kHz by a long chalk...

We all hit this face palm moments after some time.

There are instrumentation amps that do work into the 100's MHz range. A general purpose op amp should suffice. An Instrumentation amp is just easier to work with.

If you just want to change the voltage level to drive something else, a mosFET may be better suited and easier to work with. Or an optisolator.