I have been asked to answer this question for a co-worker of mine. We have a circuit that is basically a mic pre-amp/filter. It consist of a INA and a couple TLV2381's. All ICs are operating at +/- 3.3V. The normal operating current draw for the board is .225mA, but when sound is detected by the passive mic the current can jump up to 2mA depending on the amplitude of the signal. Can someone help me explain the reason for this occurring. It makes sense to me that the op amps are 'working' harder due to larger voltage swings of the signal, but this explanation seems insufficient for my colleague. They don't really teach effects on power consumption at this low of levels in school.
thanks
kyle