OPA2330 rush current

Keiichi,

The phenomenon you describe is called shoot-through-current and is a common occurrence in class AB output stage when the supply voltage is below its specified minimum value -  in case of OPA2330, the minimum specified supply voltage is 1.8V;  under such condition, the circuit is unable to bias up properly, which causes the push-pull transistors of the output stage to fully turn-on thus resulting in rush of the current from positive to negative supply.

There is not much one can externally do to eliminate the shoot-through current (it’s a function of the internal circuit topology used) other than to minimize the supply ramp up time and adding a large decoupling capacitor between the power supplies which will act as a charge reservoir providing bulk of the intermittent increase in the current.  

Placing a large resistor in series with power supply may cause more harm than good - it may prevent the circuit from ever properly biasing up when a large drop across the resistor does not allow the actual supply at pin of (V+) from ever reaching its specified minimum value.  Also, adding a large resistor in series with the power supply will modulate the signal in case of the variation in the output current, Iout (see graph of PSRRvs frequency).