• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 48 subscribers
  • Views 659 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

Max current sourced by TL081

Doug Vetter
Prodigy 200 points
Other Parts Discussed in Thread: TL081

Does anyone know the maximum current that can be sourced by the TL081 output?

Or, for that matter, why this figure seems to be omitted from datasheets for amps with JFET input stages but provided with those equipped with BJT input stages?

I've read that the TL081 has short circuit protection and the output can be shorted "indefinitely" but that's not giving me the information I need.

  • 0
    TI__Guru*** 145216 points

    Doug,

    The TL081 has 200 ohm output resistance. 

    When sourcing current , power dissipation just under  ([VCC+] - [VOUT])^2 / 200 ohms.

    When sinking current , power dissipation just under ([VOUT] - [VCC-])^2 * / 200 ohms.

  • 0 in reply to Ron Michallick
    Prodigy 200 points

    Forgive me, but it's been a long day.

    I asked for current, you provided power.  I assume that means you're suggesting I work backward from power and the thermal specs of the package I'm using to find the max power I can dissipate and hence current that can be sourced?

    Surely there must be a way to quantify or graph this in a manner consistent with the other datasheets, and if not, I am curious as to why.  In other words, how did TI arrive at the Io (output current) specification on the other datasheets I've seen?

  • 0 in reply to Doug Vetter
    TI__Guru*** 145216 points
    Doug,

    When sourcing current , maximum current is about ([VCC+] - [VOUT] - 1V) / 200 ohms.

    When sinking current , maximum current is about ([VOUT] - [VCC-] - 1V) / 200 ohms.

    The power formulas help calculate how hot the device will become.