Bias current generator for multiple supply voltage circuit

摘要

An electronic device supplied by multiple supply voltages includes a bias current generating stage and maximum current selection stage. The bias current generating stage comprises a crude bias current generator for generating an crude bias current during a power up phase in which at least one of the multiple supply voltages has not yet reached its target supply voltage level, a reference current stage for providing a reference current having a target current value greater than the target value of the crude bias current when the multiple supply voltages have reached their target supply voltage levels. The maximum current selection stage is adapted to continuously output a bias current which is the maximum current of the crude bias current and the reference current.