[op amp] maximum output current measurement

[spinner12]

Anyone has the experience of measuring maximum output current of an op amp? Thanks in advance

 

[crutschow]

The maximum output current is not normally measured, it is a specification from the op amp designer. If you need too, you can measure it by setting the output to a high or low voltage with the amp configured as a follower and loading the op amp output with a variable resistive load. You lower the load resistance until the voltage starts to drop. From the voltage and load resistance at that point, you can calculate the current.

Note that the measured value only applies to the particular unit you measured. Due to manufacturing variations, it could be more or less for other units. That is why you use the spec value when designing a circuit.

 

[spinner12]

The maximum output current is not normally measured, it is a specification from the op amp designer. If you need too, you can measure it by setting the output to a high or low voltage with the amp configured as a follower and loading the op amp output with a variable resistive load. You lower the load resistance until the voltage starts to drop. From the voltage and load resistance at that point, you can calculate the current.

Note that the measured value only applies to the particular unit you measured. Due to manufacturing variations, it could be more or less for other units. That is why you use the spec value when designing a circuit.

when you say a high or low voltage, you mean close to rail if the op amp is a rail-to-rail amp?

Thanks for your explanation. As for the specification of an op amp, some specs claim they have same short circuit output current under different power supplys, say 5 V, 10 V or 15 V, is this true? in my impression, the short circuit output current has a lot with the power supply, what's your opinion?