OPA129: Replacement of obsolete OPA129

Hi Robin,

make a search here:

and here:

Choose appropriate search parameters to narrow the search.

Kai

Hi Kai

Thank you for the links. I already searched for similar OPs but the problem is that the pinout is always different to the OPA129. That's why I asked the question to the community. Unfortunately it is not possible to filter for same pinout. I still will check if I find an alternative. If anyone has a suggestion or another idea I am lookin forward to hearing it.

Thank you.

Best regards

Morning Robin, 

looks like the old BurrBrown (1980s vintage) DiFet process is going away - that does impair availability going down the road - tough process to match exactly - whenever this happens, the product group makes some effort at pointing to an option, shown here, the tough thing is usually the supply voltage - those old BurrBrown precision parts were usually +/-15V or more - if that is what is being used (and probably not needed for a transimpedance app) going to be tough. If you can reduce the supplies down more in the range of the much newer LMP7721,you might get there with a drop in. 

Kai gave you the top level product search links - there are also cross reference tools that can show internal parametric options - here is one of those two (on the TI web site) with the OPA129 entered, sadly - that tool seems to have removed the OPA129 (an egregious error as you could use this tool to find crosses) Let me try the other one, that one shows the part but again no parametric match results - it is interesting to look at the parametrics reported - since this is a 3rd party database, always interesting to see what errors are imbedded - here that input bias current is of course way off and the status (transferred) is not accurate. Oh well, 

It is interesting to see the BurrBrown manufacturer - which is true, but hitting that drop down only shows BurrBrown and TI (no National Semiconductor, which is where the LMP7721 came from  - LMP, Linear Monolithic Precision - some real nice CMOS parts from that group). 

More modern higher voltage <5MHz GBP VFA parts do of course exist - those will be much lower supply current and offset (all good likely) - I don't have a good parametric table below 20Mhz parts, but here is an option if you can relax the input bias current requirement - looks like a standard SO-8 is available, 

The higher 2.5Mhz GBP might require a different feedback C for stability in your transimpedance app. 

Hi Michael

Thank you really much for your detailed answer. Your suggested part OPAx196 has another pinout (V- is at pin 4 instead of pin 5). That is the same problem as on all other alternatives I found. V- is always on pin 4.

Best regards

Hi Robin,

yes, the idea behind was to increase the distance between the -supply pin and the input pins, in order to reduce leakage currents. That's also the reason for the "odd" pinout of LMP7721.

Kai