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Original question:

TL081: TL081IP and uA741CP

TL081: TL031IP

toshiya kadoyama
Prodigy 70 points
Part Number: TL081
Other Parts Discussed in Thread: TL061, TL031, TLE2021

Hello

PDIP(8) is used as a replacement for obsolete products.
Initially, we considered TL081IP. but
Regarding the Temperature coefficient of input offset, we calculated it from the answer below and found it to be 150uV/℃@(25-85)℃(MAX), which is too large.
＞TL081 is 18uV/C typical, maximum wouldn't create 15mV of Vos;
I would like to adopt the TLP031IP, but please let me know the following as soon as possible.

(1) Use by attaching a 10kΩ trimmer resistor between the offset and NULL terminals and connecting the tap to -12V. at this time
ΔVIO(adj)(Offset voltage adjust range)
Does it satisfy ±15mV (TYP)?
(2) In the Input Offset-Voltage Null Circuit of TL061, a 1.5kΩ center resistor is attached to the 100kΩ trimmer resistor.
Are there any major problems when using the TLP031IP with a 10kΩ trimmer resistor and connecting the center tap directly to -12V?
(3) TLP031IP has JFET input, is there anything I should be careful about when using it?
For example, phase, gain margin, open loop gain, minimum gain, ringing due to feedback circuit response delay, etc.

Best regards

  • 0
    TI__Guru**** 151376 points

    Hello Kadoyama-san,

    Is the supply voltage 24V (+/-12V); TL031AI is factory trimmed at 30V 

    1) That would allow changing the Vos ; Does "Does it satisfy ±15mV (TYP)?" mean you want a high Vos?

    2) TL031 has fairly good Vos; you would only need to set the potentiometer close to center; so the missing resistor should not matter.

    3) TL031, TL081 (not H), TL061 are all JFET. Concerns are staying in valid input common mode range, avoid step inputs.

    TLE2021 may be a better solution; you have the option to remove potentiometer; this op amp has way better Vos and temperature drift. However input difference voltage is limited.