TL081: TL081CDR

Pearl Wen

Prodigy 10 points

Part Number: TL081

Tool/software:

With Part Number: TL081CDR

We have a suffering issue relating PCN# 20220615003.1 .

We know that this PCN change relates WAFER & FRAMEWORK & body making & Assembly site.

We're wondering if “Input offset adjustment N1,N2“ has no function withTL081CDR?

Since TL081CD replaced with TL081CDR,base on TT circuit diagram , no matter how to adjust R38,there’s no output voltage change with TACHO+ ~ TACHO+ . (R37
=5.1kohm or 1.5k ohm ).
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7 months ago

0 Clemens Ladisch 7 months ago

Guru 316920 points

The new die is identical with the TL081H and uses a different architecture, so the same offset adjustment mechanism is no longer possible. As far as I know, these pins are NC.

+1 Raymond Zhang1 7 months ago

TI__Guru* 77151 points

Hi Pearl,

Pearl Wen said:
We know that this PCN change relates WAFER & FRAMEWORK & body making & Assembly site.

Yes, the PCN was dated in 6/16/2022 and here is the link from mouser.com.

https://www.mouser.com/PCN/Texas_Instruments_PCN20220615003_20220616135610237.pdf

Pearl Wen said:
We're wondering if “Input offset adjustment N1,N2“ has no function withTL081CDR?

Please check Clemens simplified block diagram and the Vos adjustment is eliminated, likely in early revision back in 2021 (have to check early datasheet to confirm).

Could you upload two attached images again? I am unable to view the schematic.

Best,

Raymond

0 Pearl Wen 7 months ago in reply to Raymond Zhang1

Prodigy 10 points

Hi Raymond,

Thanks for your kind response.

It's really useful for us to understand the problem.

Here's our circuit diagram, could you please help to check how to modify if we still use "TL081CDR" , or what's the better solution to for our usage.

Base on our current circuit diagram , no matter how to adjust R38,there’s no output voltage change with TACHO+ ~ TACHO+ . (R37
=5.1kohm or 1.5k ohm ).

0 Pearl Wen 7 months ago in reply to Clemens Ladisch

Prodigy 10 points

Hi Clemens,

Thanks for your reply.

I've shared your reply to team. We'll confirm next solution.

Great hanks for your kind support1

+1 Raymond Zhang1 7 months ago in reply to Pearl Wen

TI__Guru* 77151 points

Hi Pearl,

Pearl Wen said:
, no matter how to adjust R38,there’s no output voltage change with TACHO+ ~ TACHO+ . (R37
=5.1kohm or 1.5k ohm ).

Yes. This is the current behavior on these pins - the Vos trim feature has been disabled or not implemented in the post PCN op amp. If the Vos is higher than your requirements, you may have to change to lower offset op amp (easiest solution - Other Vos trim method may require to re-spin the PCB).

Best,

Raymond

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TL081: TL081CDR