When a local circuit block of an integrated circuit is powered down, a very small reference current from a bandgap or a reference current generator often bleeds. FIG. 1, for example, is a schematic diagram illustrating a portion of an exemplary circuit 100 in which a small current bleed is present. Specifically, when the circuit 102 on the supply voltage (AVCC) domain is powered down, a small reference current (Ire) from the termination supply voltage (AVTT) domain bleeds constantly. Although this bleed of small current is insignificant when compared to the overall power consumption of the circuit 100, the trend toward lower power devices disfavors even a small current bleed.
Some designs are able to minimize current bleed during power down at the expense of performance in some process, voltage supply, and temperature corners. Other designs minimize the negative effects on certain process corners, but are less reliable. Still other designs improve reliability, but are susceptible to voltage drops and/or create noise which may adversely affect noise sensitive circuits.