Methods and apparatus provide for enabling a digital circuit by biasing at
least one switch transistor ON such that a voltage potential of a virtual
ground node is substantially equal to a voltage potential of a ground
node for a power supply to the digital circuit, wherein the digital
circuit is implemented using a plurality of transistors in a
silicon-on-insulator (SOI) arrangement and at least some of the
transistors are referenced to the virtual ground node; and disabling the
digital circuit by biasing a gate terminal of the switch transistor below
the voltage potential of the ground node.