TL082: How to measure the open loop gain of TL082?

Hi Ken, 

Ken Zhang said:

A my account wants to know how to measure the open loop gain of tl082. which equipment are used in TI for open loop gain measure? any recommendation equipment for open loop gain measure?

This is one of the technique to simulate in Tina or other tool, which is similar to a lab measurement. 

BTW, TL082 has issued PCN recently, and the current op amp is manufactured from the RFAB, and it is different from the simulated model (the technique is the same). 

https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/5488/PCN20230627002.1.pdf

TL082 Aol Simulation 05092025.TSC

To do this properly in the lab, you would need a network analyzer and injection transformer. For lower cost approach, you can get Bode 100 and Picotest J2100A Injection Transformer, see the link below. 

https://www.omicron-lab.com/fileadmin/assets/Bode-Analyzer-Suite/Documents/Bode-Analyzer-User-Manual.pdf

https://www.signaledgesolutions.com/product-page/picotest-j2100a-injection-transformer-1hz-5mhz

In addition, we have op amp training video, can be found in the following link. 

https://www.ti.com/video/series/precision-labs/ti-precision-labs-op-amps.html?keyMatch=precision%20op%20amp%20lab%20training%20video&tisearch=universal_search

If you have other questions, please let me know. 

Best,

Raymond

Hi Ken, 

Please contact me via TI internal email. This query is a public forum and I can not show you the circuit in the platform. 

We do the open-loop gain circuit similarly. It is all the same theory with minor different implementation, where LoopGain = Aol/Acl, if you know any of two two parameter, you can plot out the third. So if you know Acl and Loopgain, then you can calculate Aol and vice versa. 

This is stated in the video training below. 

https://www.ti.com/video/series/precision-labs/ti-precision-labs-op-amps.html?keyMatch=precision%20op%20amp%20lab%20training%20video&tisearch=universal_search

Best,

Raymond