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TLV9061: Max Input Bias Current

Hao Wang14
Expert 4415 points
Part Number: TLV9061
Other Parts Discussed in Thread: OPA348, , LMC6081, OPA320, LMP7721, LMP7711, LMV796, LMP7715, OPA322, OPA316

Hi Team,

The datasheet only has the typical value of input bias current, but some other device such as OPA348 has both typical and max value, so my questions are:

1. What's the max input bias of TLV9061?

2. Will the input bias current vary greatly within mass production devices such as 100,000 pieces?

Thanks and Best Regards!

Hao

  • 0
    TI__Guru**** 151466 points

    Hao,

    1) There is no maximum IIB value. 

    2) My best guess is that most 100k unit groups would not see over 3pA.  If current was higher (and it mattered to the application) , there wold be no other option than re-working the board and moving on as the device would not be defect per the data sheet.

    IIB tends to increase exponentially with temperature so that must only be considered. The data sheets have typical charts for temperature effect. The charts are just typical input bias current behavior not a maximum current.

      

  • 0
    Guru 140200 points

    Hi Hao,

    the TLV9061 is a very low cost OPAmp. Because of this for the input currents only typical specifications are given in the datasheet.

    Kai

  • 0 in reply to Ron Michallick
    TI__Expert 4415 points

    Hi Ronald,

    Thanks for confirming the max IIB, as there is no specific data about the max value, customer may still concern about it because their application requires the IIB varies not that much for different units.

    Is it right that low cost amplifier doesn't have the max specs as Kai replied which can further help save cost? If so, could you please help recommend some other low cost amplifier with max IIB value in datasheet which is similar to TLV9061? The other key specs including noise and GBW should be at least no worse than TLV9061.

    Thanks and Best Regards!

    Hao

  • 0 in reply to Hao Wang14
    Guru 140200 points

    Hi Hao,

    you might want to have a look at the OPA320, LMP7711, LMP7715, LMV796, LMC6081 or LMP7721.

    Or have a look for yourself:

    Kai

  • Former Member
    0 Former Member in reply to Hao Wang14

    Hello Hao,

    Some low-cost amplifiers do have this specification.  But, it is more common with some of our older parts.  TLV9061 is newer and does not have this specification.  It's probably true that, in general, getting this maximum specification will require more cost.

    I ran a search based upon rail-to-rail input and output, bandwidth, voltage noise, and max offset voltage.  If you want a part that is as good or better than the TLV9061 in all these areas and also has a bias current guarantee for the lowest online price, I would suggest the OPA322.  Note that the offset for this part may be slightly worse.  Alternatively, if you don't need all that performance you might look into the OPA316.

    Kai's suggestions may also be of use, but will probably be higher cost.

    Please let us know if you need any further help.  If there is a specification that I have considered but is not as important, then we may be able to find a better fit.

    ► Part Number TLV9061 OPA316 OPA322
    Manufacturer TI TI TI
    Num Channels 1 1 1
    Vs min (V) 1.8 1.8 1.8
    Vs max (V) 5.5 5.5 5.5
    GBW (MHz) 10 10 20
    Slew Rate (V/us) 6.5 6 10
    Vos max @ 25C (mV) 1.5 2.5 2
    Drift typ (uV/C) 0.3 2 1.8
    Rail-to-Rail In, Out In, Out In, Out
    Iq typ (mA) 0.538 0.4 1.6
    Vn (nV/rtHz) 16 11 8.5
    Isc typ (mA) 50 50 65
    Ibias max (pA) --- 15 10
    Operating Temperature (°C) -40 to 125 -40 to 125 -40 to 125
    Additional Features Cost Optimized | EMI Hardened | Small Size Small Size | EMI Hardened Shutdown
    Available Packages SC70 | SOT-23 | SOT-23 | X2SON SC70 | SOT-23 SOT-23 | SOT-23
    Price (1ku web $) $0.15 $0.40 $0.55

    Regards,

    Daniel

  • Former Member
    0 Former Member in reply to Former Member

    Looking more closely, Kai's suggestion of the LMV796 may also fit.  Just note that it does not have the same input or output swing.  So this would be the main downside.  It may not be necessary for the customer's application, however.

    ► Part Number TLV9061 OPA316 OPA322 LMV796
    Manufacturer TI TI TI TI
    Num Channels 1 1 1 1
    Vs min (V) 1.8 1.8 1.8 1.8
    Vs max (V) 5.5 5.5 5.5 5
    GBW (MHz) 10 10 20 17
    Slew Rate (V/us) 6.5 6 10 9.5
    Vos max @ 25C (mV) 1.5 2.5 2 1.35
    Drift typ (uV/C) 0.3 2 1.8 1
    Rail-to-Rail In, Out In, Out In, Out In to V-, Out
    Iq typ (mA) 0.538 0.4 1.6 1.15
    Vn (nV/rtHz) 16 11 8.5 5.8
    Isc typ (mA) 50 50 65 21
    Ibias max (pA) --- 15 10 1
    Operating Temperature (°C) -40 to 125 -40 to 125 -40 to 125 -40 to 125
    Additional Features Cost Optimized | EMI Hardened | Small Size Small Size | EMI Hardened Shutdown N/A
    Available Packages SC70 | SOT-23 | SOT-23 | X2SON SC70 | SOT-23 SOT-23 | SOT-23 SOT-23
    Price (1ku web $) $0.15 $0.40 $0.55 $0.51

    Regards,

    Daniel

  • 0 in reply to Hao Wang14
    TI__Guru**** 151466 points

    Hao,

    So the variance in IIB matter more than the absolute value of IIB?  That may be true up to a point.

    Were any the the op amps listed by Kai and Daniel acceptable?

  • 0 in reply to Ron Michallick
    TI__Expert 4415 points

    Hi Ron,

    Yes, the variance matters more because customer doesn't want few failure due to the large variance in mass production, maybe the device such with max value such as OPA316 and OPA322 is more reliable, we will try these two devices first. 

    Thanks and Best Regards!

    Hao

  • 0 in reply to Hao Wang14
    TI__Guru**** 151466 points

    Hao,

    Very good. Feel free post post again if further questions arise.