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LMC6035: Maximum Sink/Source Current

Don Schelle
Expert 4150 points
Part Number: LMC6035


Folks,

I have a question regarding the maximum sink/source current or the LMC6035.

The Abs Max table suggests that the maximum output current is +/-18mA with 30mA as an acceptable short-term value (note 5).

Though the typical output current as shown in Figure 4 and Figure 6 suggests that 100mA is possible:

Couple of questions:

1. What is the maximum allowed output current?

2. Can you quantify the amount of time that would be considered "long term" in the abs max table?

Don

  • 0
    TI__Guru**** 165566 points

    Hello Don,

    LMC6035 is usually selected for the low input bias current. So trying to get a lot of output current will just make the LMC6035 warmer which is counterproductive to getting low input current. There are other op amps that are far better giving high output current.

    1) 18mA but limited such that junction temperature is less than 150C.

    2) Not really. However, the claim peril is reliability not imminent demise. So I'd take a wild guess and say many hours.

  • 0
    Guru 48395 points

    Well DOn, those curves are very confusing, seemed like they might be reversed axis or something? In any case, the electrical table says this - so not much apparently can be expected for output current. The absmax table is an electromigration calculation for continuous operation at the current for years. 

  • 0 in reply to Ron Michallick
    TI__Expert 4150 points

    Thanks Ron,

    Are the scales in figures 4 and 6 correct, or is this a typo?   They would seem to imply that the op-amp is capable of delivering far more current than the abs-max would suggest.    Further the figures also imply that operating at higher output currents is not only possible, but also encouraged as they are located in the section titled "Typical Performance Characteristics".

    Don

  • +1 in reply to Don Schelle
    TI__Guru**** 165566 points

    Don,

    Figure 4 and 6 are correct. That data coupled with figures 5 & 7 show the the op amp will provide as much current as the output transistors can provide with the full gate voltage (applied internally from Vs). There clearly is no internal current limit circuit. Therefore the application must ensure the a safe current level is not exceeded. The op amp can not protect itself from over current nor over temperature.

    We do have other op amps that do have current limit and over temp shutdown.