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LPV542: Is there detailed offset voltage data?

Part Number: LPV542
Other Parts Discussed in Thread: LPV521, TLV8802, TLV8542, LPV812, TLV8812, LPV821,

Is there detailed information anywhere about the input offset voltage for this opamp?  Perhaps some graphs, similar to the graphs (figures 3-22) in the LPV521 datasheet?

  • David

    I’ll look for characterization data tomorrow that may help. Not sure what your operating voltage is but the tlv8542 and tlv8802 are other options for you to consider.

    Chuck

  • Thanks Chuck,

    My operating voltage is 2.25 volts to 3.3 volts (lithium coin cell). I'm using these as transimpedence amps for a pair of photodiodes. One diode is in photoconductive mode, and the other is in photovoltaic mode. So in the first case, CM voltage is 1V, but in the second case, CM voltage is zero.

    The TLV8802's bias current goes way up with temperature. But wow, the TLV8542 looks great!  It will all come down to how the offset voltages compare, I think.


    David

  • David
    Don’t be too worried about bias current slightly below ground unless you are forcing it below the standard offset voltage range. We’ve got several customers using these parts at a common mode of 0v for their 2 wire gas sensing applications. In regards to bias current increasing with temperature, there isn’t much we can do to combat the 2x increase per 10c change in temperature. However some parts start lower at room temperature as you noticed. The lpv812 has very good offset if you want to take a look. The tlv8812 is the lower cost version that still has good warranty spec. We spent a lot of time developing parts in this area, so that’s why we have so many devices. If you’re really interested, check out the lpv821 which is the only nanopower zero drift amp in the market. 10uv offset max may be overkill for you but it’s available if you ever need it but only single channel available currently.
    Chuck
  • Thanks Chuck. For my application, it's more important to maintain extremely low bias currents, which is why I'm looking at the LPV542 and TLV8542. If I'm clever, then the offset voltage will cancel. Still, it's nice to have full specs, so please let me know if you can find any data for LPV542 offset voltage.
  • David

    Unfortunately I only found offset distribution data around the points that are listed in the EC table (VCM of 300mV above the negative rail and below the positive rail at the 3 different power supply voltages).   I have reached out to members of the original team to see if there is additional data stored elsewhere.  I will send a second response to this post regardless to let you know.

    Chuck

  • David
    Sorry for the delayed response. I meant to tell you that I was unable to find any additional offset data on the LPV542.
    Please feel free to open a new thread if you need any additional information on the other devices.
    Chuck
  • Hmm. That's disappointing. Offset voltage is an important feature, so data should be made available for this part.