A power switching circuit is provided for use in an integrated circuit
including at least a first voltage rail and a second voltage rail. The
power switching circuit includes at least one MOS device having a first
source/drain adapted for connection to the first voltage rail, a second
source/drain adapted for connection to the second voltage rail, and a
gate adapted for receiving a control signal. The MOS device selectively
connects the first voltage rail to the second voltage rail in response to
the control signal. The first and second voltage rails form a grid
overlying the power switching circuit, the first and second voltage rails
being formed in different planes relative to one another. The connection
between the power switching circuit and the first voltage rail is made at
an interface between the first and voltage rails.