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Original question:

TL081: TL031IP

TL081: TL031IP

toshiya kadoyama
Prodigy 70 points
Part Number: TL081
Other Parts Discussed in Thread: TL061, , TL031, TLE2021, UA741

Hello Ron Michallick

Thank you for your reply regarding TL031IP.
Please continue to answer the questions marked with "→".

>Is the supply voltage 24V (+/-12V); TL031AI is factory trimmed at 30V
→TL031IP is used at 24V (+/-12V).

> That would allow changing the Vos ; Does "Does it satisfy ±15mV (TYP)?" mean you want a high Vos?
→
(1) It is not intended for high Vos.
(2) I would like to know if it is possible to connect a 10kΩ trimmer resistor to the TL031IP and adjust it within the range of ±15mV (TYP) like the conventional products, UA741CP, and LM741CN.
Please tell me the ΔVIO(adj) (Offset voltage adjustment range) of TL031IP.
(3) Will connecting a 10kΩ trimmer resistor to the TL031IP and adjusting it cause the element to break?
(4) How is ΔVIO(adj) calculated?

>TL031, TL081 (not H), TL061 are all JFET. Concerns are staying in valid input common mode range, avoid step inputs.
→In the case of TLP031IP, how much value should I be careful about step input?

>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.
→TLE2021IP cannot be adopted because it is in "LIFEBUY" status in the data sheet.

Best regards

  • 0
    Prodigy 70 points

    Part Number: TL081

    Hello Ron Michallick

    The reason I'm asking this question is
    I am looking for a replacement for another company's 741 that does not require changes to the board pattern or constants.
    This is because the UA741CP and LM741CN/NOPB do not satisfy the temperature range, so we are considering whether another type of product can be used.

    Best regards

  • 0 in reply to toshiya kadoyama
    TI__Mastermind 19607 points

    Hello Kadoyama-san, 

    Please confirm this is the following pinout you would like to drop in replace: 

    Any additional system requirements? 

    • Power Supply 
    • Expected input/output 

    All the best,
    Caro

  • 0
    Prodigy 70 points

    Part Number: TL081

    Hello Caro

     

    The pin arrangement is as attached.

    Please respond to my question as soon as possible.

     

    Best regards

  • 0 in reply to Caro Walter
    Prodigy 70 points
    • Power Supply: t 24V (+/-12V).
    • Operating Temperature Range:-20 to +85 ℃
  • 0 in reply to toshiya kadoyama
    TI__Mastermind 19607 points

    Hello Kadoyama-san, 

    In that case, the following part numbers can replace: 

    P2P: 

    No offset trim but still P2P: 

    • TL061IP

    As you'll see none of these are rail to rail, could you please specify the expected input/output? 

    toshiya kadoyama said:
    >TL031, TL081 (not H), TL061 are all JFET. Concerns are staying in valid input common mode range, avoid step inputs.
    →In the case of TLP031IP, how much value should I be careful about step input?

    Please only hit "Reply" not "Ask a new question" as this creates a new thread and I have to merge them each time. 

    Thank you. 

    All the best,
    Carolina 

  • 0 in reply to Caro Walter
    Prodigy 70 points

    Hello Caro

    Thank you for suggesting alternatives.
    Other required specifications are as follows.
    ・Expected input/output：
    　VID=±3V(MIN)
    　output voltage swing=±6V(MIN)
    ・Input offset voltage =±6mV(MAX)@25℃
    ・Temperature coefficient of input offset voltage=±30uV/℃(MAX)
    ・Input offset voltage adjustment range=±15mV(TYP)
    ・Offset Nulling Circuit: Diagram below

    I'm sorry for asking "Ask a new question" every time.
    From now on we will use "Reply".


    Best regards

  • 0 in reply to toshiya kadoyama
    TI__Mastermind 19607 points

    Hello Kadoyama-san, 

    I understand now and also understand Ron's response from above, the TL031IP is well within the requirements you have specified above: 

    Here is a comparison of the ones I suggested above, as you can see the variable is the gain bandwidth. Could you please share if there are input frequency requirements? Assuming the gain is 2. 

    The uA741 has a large resistive drive capability compared to the other ones, is there anything connected to the output of the op amp? resistor/capacitor to gnd? long cable? 

    All the best,
    Carolina 

  • 0 in reply to toshiya kadoyama
    TI__Mastermind 19607 points

    Hello Kadoyama-san, 

    Thanks for sharing the schematic. I am going to delete it since this is a public forum. 

    I encourage you to order samples from the suggestions through your regional sales contact -- if you do not know who this is I can help identify them.

    Please test the samples on a prototype board and let us know if they work for the application. I expect them all to work. 
    If you run into any issues, try removing C1, C4, and C5. This is a no longer recommended way of filtering the input. 

    All the best,
    Carolina 

  • 0 in reply to Caro Walter
    Prodigy 70 points

    Hello Carolina-san,

    Thank you for your reply.
    Samples are currently being ordered.
    I will try removing C1, C4, and C5 if I have a problem.
    However, what I would like to know immediately are the answers to (2) to (5) below.
    (especially (2)(3)(5))


    (2) I would like to know if it is possible to connect a 10kΩ trimmer resistor to the TL031IP and adjust it within the range of ±15mV (TYP) like the conventional products, UA741CP, and LM741CN.
    Please tell me the ΔVIO(adj) (Offset voltage adjustment range) of TL031IP.
    (3) Will connecting a 10kΩ trimmer resistor to the TL031IP and adjusting it cause the element to break?
    (4) How is ΔVIO(adj) calculated?
    (5)In the case of TLP031IP, how much value should I be careful about step input?

    Best regards,

    Kadoyama

  • 0 in reply to toshiya kadoyama
    TI__Mastermind 19607 points

    Hello Kadoyama-san, 

    Regarding your questions, there is very limited information since these parts are older and the datasheet does not specify. 

    I did however find the following thread: https://e2e.ti.com/support/amplifiers-group/amplifiers/f/amplifiers-forum/968257/tl031-offset-adjustment

    It says "the TL031 is a "direct upgrade" for the TL061, you can do the offset adjustment like it's done with the TL061"
    Therefore I would expect Figure 7-2 to work: 

    I do not know the answer to 3 and 4. 
    Please reference the following application report: Nulling Input Offset Voltage of Operational Amplifiers

    I do not think the calibration is necessary as the TL031 is already within the offset requirements of the application. I would first recommend to test without connecting the potentiometer to offset1 & offset2. 

    All the best,
    Caro