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TLV2186: Output short-circuit sink current when sinking current

Part Number: TLV2186


I have a question regarding the max. output current of the op amp TLV2186.
According to the datasheet, "Short-circuit to ground: continuous", it is safe to short the op amp output to ground.

But what about shorting the output e.g. to the positive supply rail?

Consider this case: the op amp is supplied by single-supply 12V and configured as voltage follower. The input is 0V, but the op amp output is connected to +12V.
The op amp will try to output 0V, but due to the short-circuit, it can't and a current will flow into the opamp output.

Will the current still be limited, or would this destroy the op amp?

Under "electrical characteristics", the short circuit output current is specified as +/-20mA (positive and negative) , so can I assume that the output is also protected wen sinking and not sourcing current?

Thanks in advance for your help!


  • Hello Marcel,

    An output short to ground, or a supply is a concern because the op amp power and internal power dissipation can surge during the event. The risk is if the junction temperature (Tj) of an output transistor becomes too high (Tj > 150°C). If that should occur the output transistor in the op amp could become damaged.

    The condition for an output short-circuit is typically specified either to ground, or to mid-supply, to keep the power dissipation to a level where Tj does not exceed 150°C when the output short-circuit current (Isc) is flowing. If you think about the condition where an op amp is being powered by a dual supply such as +/-15 V, the voltage across the output transistor supplying Isc is 15 V, and the power is 15 V x Isc. When the output is shorted directly to one of the supplies in the +/-15 V case, then 30 V would be applied across the transistor supplying Isc and power dissipation would double. Depending on the op amp thermal resistances the resulting Tj may exceed 150°C.

    Your inquiry has the TLV2186 operating from a single +12 V supply, and the follower output shorted to +12 V as well. Since the input is at 0 V the output would try to be as close to 0 V as it can got, but instead is being forced to +12 V. That places 12 V across the lower internal output transistor which would sink Isc from the +12 V supply to ground. The typical Isc is +/-20 mA for the TLV2186.

    The important point is to make sure the output transistor Tj doesn't exceed 150°C. Applying a simple formula Tj can be approximated by:

    Tj  = TA + Pd(RθJA) = TA + (VDD)(Isc)(RθJA)

    RθJA, the Junction-to-ambient thermal resistance, is listed in the datasheet as 129.4°C/W for the 8-pin SOIC package. TA will be assumed to be 25 C. Then:

    Tj = 25°C + (12 V)(0.02A)(129.4°C/W) = 56°C

    That is well below the 150°C and there shouldn't be a thermal issue in this case unless TA is much higher than assumed. It is highly likely the TLV2186 will withstand this short condition. However, the TLV2186 datasheet does not make any assurances beyond what is stated regarding that for a short to ground i.e Note (2) Short-circuit to ground, one amplifier per package. The user assumes responsibility for any outcome for unspecified output short-circuit conditions.

    Regards, Thomas

    Precision Amplifiers Applications Engineering