Low power startup circuits for voltage and current reference with zero steady state current

A class of new startup circuits for voltage and current reference circuits is proposed. Unlike conventional startup circuits, the proposed circuits completely turn off once the reference circuit is started and consume no current during normal operation of the reference circuits. The circuits employ feedback from the reference circuit to ensure that the latter has reached its desired operating state prior to shutting themselves off. The proposed circuits are useful in low power integrated circuit design. Very low startup time can be achieved. The circuits are generic in nature and can be used with any reference circuit such as bandgap voltage references and ΔVgs/R circuits.