Max current sourced by TL081

Doug Vetter

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.

over 8 years ago

0 Ron Michallick over 8 years ago

TI__Guru*** 136226 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 Doug Vetter over 8 years ago 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 Ron Michallick over 8 years ago in reply to Doug Vetter

TI__Guru*** 136226 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.

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Max current sourced by TL081