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Please try to define your requirements more closely. Do you mean an opamp with very low offset voltage? What about speed, input bias current, supply voltage, noise, etc.?
My requirements are to measure a signal of 10mV peak, so I want really low offset voltage preferably with no offset trim pins
low frequency.
Speed is not and issue.
Input bias current relatively low.
Supply Voltage +/-9v - +/- 12V (dual supply)
CMRR of over 40dB
An opamp cannot "measure", but amplify an incoming signal.
I suppose you want to amplify a 10 mV signal - and regarding offset the required signal gain is important.
For a signal gain of - let's say - 20 dB and an input offset of 1 mV the output offset will be approx. 1uV or less. Is this an issue? Correction: output offset 10 mV (typo).
I guess the venerable OP-07 will be suitable. I don't know how much it costs these days but it can't be very expensive as it's been around for a long time. What I recall off the top of my head: 30uV offset, 1.2nA bias, 3-18V supply; speed around the same as a 741, same pin-out, fairly low noise.
Sry about the "measure" term.. this is because my op amp will be used in a simple instrumentation amplifier (a 3 opamp one).
I will set a linear gain of 25. Can you explain the offset part again pls? 1mV -1uV ?
CA 3140 op amp I found good over ua741 rating also has good offset control range too also normal opamp in India is 5 INR loacal market where as CA3140 is arround 20 INR...so not that much costly even ..... I had used them in milivolt range -500mv to +500mv for detection.....one important thing about this opamp is it has very high input impedance....refer -
Sry about the "measure" term.. this is because my op amp will be used in a simple instrumentation amplifier (a 3 opamp one).
I will set a linear gain of 25. Can you explain the offset part again pls? 1mV -1uV ?
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