A level shift circuit for providing predictable outputs when VDDH is
powering up and minimizing DC current when VDDL is powering up. The level
shift circuit may have a control circuit that includes a first inverter
with an input coupled to VDDL, one or more diodes coupled between the
first inverter and its powering voltage supply, a second inverter coupled
to an output of the first inverter (optionally coupled to its voltage
supply via one or more diodes), a third inverter coupled to an output of
the second control inverter, an NMOS transistor coupled to an output of
the third inverter that forces the output of the level shift circuit to
the ground voltage when enabled, and a PMOS transistor coupled to an
output of the third inverter that disconnects a portion of the level
shift circuit, and thus the output of the level shift circuit, from VDDH
when disabled.