TL082-Q1: Stability issues

Zoe Yang

Intellectual 2210 points

Part Number: TL082-Q1
Other Parts Discussed in Thread: TINA-TI, TL082

Dear team,

Please help check if there were any stability issues based on below schematic provided by customer.C143=2.2uF

Do we also have internal block schematic simulation model?

over 2 years ago

0 kai klaas69 over 2 years ago

Guru 140200 points

Hi Zoe,

the phase margin of your circuit is 0° and your circuit is instable. See the result of the phase stability analysis performed with TINA-TI:

zoe_tl082.TSC

Kai

0 kai klaas69 over 2 years ago

Guru 140200 points

The "dual feedback method" can be used to provide a sufficient phase lead and to make the circuit stable. This is one of many similar circuits which will be stable:

Kai

0 kai klaas69 over 2 years ago

Guru 140200 points

Also watch this very nice TI's training video series on stability:

https://training.ti.com/node/1138805

The "dual feedback method" is explained in detail there.

Kai

0 Jerry Madalvanos over 2 years ago in reply to kai klaas69

TI__Mastermind 28116 points

Kai, thank you for providing the stability analysis!

Hey Zoe,

While Kais method will give you more stability, it should be noted that the model for the TL082 does not necessarily accurately model stability. It is a fairly old model. Simulation may get you close (and there is plenty of headroom in Kais simulation) but for the most certainty in the results I would recommend testing on a bench setup if possible.

Best,
Jerry

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TL082-Q1: Stability issues