A circuit for applying power to mixed mode integrated circuits in a predefined
sequence. The circuit includes a first circuit powered by a first voltage and a
second circuit powered by a second voltage that is less than the first voltage
and having the second voltage coupled to the first circuit. The circuit for applying
power to mixed mode integrated circuits includes a modified I/O cell of the second
circuit. The modified I/O cell has a driver transistor including a back gate terminal,
a gate terminal that is driven by the second circuit, a drain terminal that is
coupled to a first circuit signal, and a source terminal that is coupled to the
second voltage. The circuit for applying power to mixed mode integrated circuits
further includes a controller circuit coupled to the first voltage and the second
voltage supplied as controller circuit inputs. The controller circuit has a plurality
of controller circuit outputs. The circuit for applying power to mixed mode integrated
circuits also includes a back gate bias application circuit. The back gate bias
application circuit has a plurality of inputs coupled to the plurality of controller
circuit outputs, and an output coupled to the back gate of the driver transistor
back gate terminal.