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TLV2172-Q1: short-circuit current definition

Josef Warta
Expert 4550 points

Part Number: TLV2172-Q1

Hello Team, my customer has following question:

In the datasheet (SBOS784C –NOVEMBER 2016–REVISED JANUARY 2019), short-circuit current is defined as shown below.

I want to make sure that my understanding is correct, and I was hoping you could help.

 

In our case, the operational amplifier is configured to output either 5V or 8V5 at Pin1 (with feedback on Pin2). Now, let’s suppose that a short to ground occurs at this pin (OUT A).

Does the definition below mean that the current will be internally limited to 75mA (typical)? If yes, is there timing limitations to this protection feature? Or can this current be applied continuously?

Many Thanks

Josef

  • 0
    Guru 325520 points

    There is no explicit protection feature. The output simply does not have enough drive strength to source or sink more current. As shown in figure 5, the exact limit varies greatly with temperature, but the absolute maximum ratings (section 6.1) guarantee that one output can be short-circuited continuously.

  • 0
    TI__Guru**** 174306 points

    Josef,

    In general, avoid doing anything to a real op amp that would be meaningless (no effect) or creates an infinite magnitude response when used with an ideal perfect op amp. Such things are direct output capacitance and short circuits. The reason is that the circuit response will be no longer be based solely on the other components in an op amp circuit. The op amp itself could increase the variability in results. For a short, add some series resistance so the application sets the "short" current. 

    One amplifier can be shorted directly as an absolute maximum rating. So it is not recommended usage. Also note ABS MAX junction temperature is 150C, if the continuous short causes the junction temperature to rise above 150C then the usage exceeds ABS MAX table. This would be more likely if supply voltage is high.