• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 47 subscribers
  • Views 457 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

INA114: replace from INA131BP

ttd
Mastermind 9305 points

Part Number: INA114
Other Parts Discussed in Thread: INA821, INA819, INA818, INA333

Tool/software:

Dear Technical Support Team,

INA131BP is already EOL.

So are there any circuit designs that use the INA131AP or INA114BP to complement the performance(such as offest voltage etc) of the INA131BP?

Best Regards,

ttd

  • 0
    TI__Mastermind 30480 points

    Hi ttd,

    Would the customer(s) be interested in moving from a PDIP to a surface-mount device? That will help open up more options to them.

    The INA114BP won't actually have a much larger maximum offset voltage compared to the INA131BP. The difference being only 0.5uV with a Gain of 100 V/V. 

    The difference in offset voltage drift is more significant in the INA114BP than the INA131BP. 

    Are you looking to factor out the offset voltage through digital or through analog? 

    Best Regards,

    Robert Clifton

  • 0 in reply to Robert Clifton56
    Mastermind 9305 points

    Hi Robert,

    Thank you for your reply.

    Thank you for your reply.

    Since INA131BP is already in mass production, a pin-compatible PDIP device with equivalent performance (offset, drift, etc.) would be ideal, but I haven't found any from TI. If you have any recommendations for surface-mount devices, please let me know. Perhaps the INA818, INA821, or INA819?

    Instrumentation amplifiers product selection | TI.com

    Also, the INA131AP has "FIGURE 2. Optional Trimming of Output Offset Voltage." Is this circuit capable of adjusting the offset to 50uV, equivalent to the INA131BP? Since this would require changing the board, I think it would be more practical to use a newer INA8xx.

    ...

    You said:

    Are you looking to factor out the offset voltage through digital or through analog?

    →Digital means caliration of  the offset voltage after acquiring data with the ADC, while analog means using an external analog circuit for OFFSET trimming, as mentioned in FIGURE 2 ?

  • +1 in reply to ttd
    TI__Mastermind 30480 points

    Hi ttd,

    PDIP is a legacy package that doesn't see many customers continuing to use compared to other devices. Our newer devices tend to skip PDIP completely. 

    Are the customers using the high voltages? If they are using supply voltages of up to 5.5V, then the INA333 is a great device to use. 

    The big concern with replacing any instrumentation amplifier would be the input common-mode voltage vs output voltage could vary. Looking at the INA818 vs the INA131BP, you will see that their output range vs common mode voltage is similar but slightly different. Depending on what the customer's input common mode range is and needed output.

    INA131BP INA818

    Highly recommend taking a look at the Analog Engineer's Calculator to verify on a case-by-case basis. 

    ttd said:

    Are you looking to factor out the offset voltage through digital or through analog?

    →Digital means caliration of  the offset voltage after acquiring data with the ADC, while analog means using an external analog circuit for OFFSET trimming, as mentioned in FIGURE 2 ?

    Figure 2 is showing a more manual analog process where you have a potentiometer that adjusts the REF pin to get the output to be whatever the desired voltage is without the offset voltage. 

    A digital solution sometimes involves during system startup for the ADC to read the 0V measurement, seeing how off from zero it is, and then adjusting through code to factor it out. Not all systems can do this of course. It's just another option.

    Best Regards,

    Robert Clifton