Selectable power supply lines for isolating defects in integrated circuits

An integrated circuit providing selectable power supply lines for isolating defects manifested by unusual quiescent current levels. During normal operation, a unitary power supply line provides power to different sections of the integrated circuit. In accordance with the present invention, the unitary power supply line is decoupled from the sections of the integrated circuit and power is provided by the selectable power supply lines during failure analysis of the integrated circuit. A section of interest of the integrated circuit is first placed in a static test state in which defects in the section may produce unusual quiescent current levels. A selectable power supply line for providing power only to the specified section of the integrated circuit is the activated by an enable signal provided to a switch coupled to the selectable power supply line. The switch allows for decoupling of the unitary power supply line from the selectable power supply line. By powering the section of interest with a dedicated power supply line, automated test equipment (ATE) can be utilized during production testing to identify areas of unusual quiescent current consumption and defect localization time for the integrated circuit is significantly reduced.