AD 542J (AD544, AD 711

[frantisek]

Greetings! Buy 2 pieces AD542J, AD544 or AD 711. Please help !!

[_Wim_]

The AD711 is readaly available from mouser and farnell (and many others)

https://be.farnell.com/search?st=ad711
https://www.mouser.be/Analog-Devices-Inc/Semiconductors/Amplifier-ICs/Precision-Amplifiers/AD711-Series/_/N-9rtls?P=1yyhd6lZ1yyh4l4

Is you need the TO-99 package, the AD544 is commonly available in that package on Ebay:

https://www.ebay.de/itm/2-Stuck-AD544KH-Analog-Devices-High-Performance-BiFET-OP-TO99/221537575119?hash=item3394ab20cf:g:hNkAAOSw7NNT27Y2

[Kleinstein]

Those OPs have a pretty standard pin-out. So chances are good a different more modern OP can be used. However the replacement may depend on the application.

OPA130 could be a reasonable good match for the AD544/542.

[frantisek]

Thanks, I'll try. The OPA 130 does not have the above-mentioned slew speed.

[Kleinstein]

There are plenty of fast modern JFET OPs to chose from - the OPA130 is more like a rather slow one with not to much noise or drift. So it really depends on the application - so hard to give a universal replacement. For high speed, low noise, something like OPA140, OPA145 or OPA197 have quite good performance and could be an upgrade is many cases.