Ok so, say you have a summing amplifier that is inverted. So the output is a negative voltage.
Nothing to extraordinary. The non-inverting terminal is grounded
The inverting terminal is the collection point obviously for the voltages to be summed.
the voltage at the inverting terminal is ~0 and the output voltage is say -5v
The feedback resistor is is 5k
So the feedback current is just 1 mA
So here is my question. on a normal op amp circuit that has some positive output voltage i would tell you that the current consumed by the op amp was just the supply current plus the feedback current. Normally obviously the output would have to supply the feedback current.
In this case, the current is supplied the other way. Its coming from the voltage devices it is trying to sum. So i would of thought that the supply current is just the supply current since the feedback current is not coming from the op amp source.
However i am not seeing that in the sim. The op amp supply current (into the supply pin) is still much higher then just what the supply current should be
Why is this?
Nothing to extraordinary. The non-inverting terminal is grounded
The inverting terminal is the collection point obviously for the voltages to be summed.
the voltage at the inverting terminal is ~0 and the output voltage is say -5v
The feedback resistor is is 5k
So the feedback current is just 1 mA
So here is my question. on a normal op amp circuit that has some positive output voltage i would tell you that the current consumed by the op amp was just the supply current plus the feedback current. Normally obviously the output would have to supply the feedback current.
In this case, the current is supplied the other way. Its coming from the voltage devices it is trying to sum. So i would of thought that the supply current is just the supply current since the feedback current is not coming from the op amp source.
However i am not seeing that in the sim. The op amp supply current (into the supply pin) is still much higher then just what the supply current should be
Why is this?