Level shifter apparatus and method for minimizing duty cycle distortion

Abstract

A level shifter apparatus and method for minimizing duty cycle distortion are provided. The level shifter includes a bank of comparators each having an associated threshold built into it. The comparators compare a difference in source voltages for two power domains to these built-in thresholds and output a signal indicative of whether the threshold is exceeded. The output signals from the comparators are provided to a thermometric decoder which generates control signals based on these output signals. The control signals are used to control stages in a level shifter for modifying the voltage output of the level shifter. Individual stages may be enabled to thereby monotonically modify the voltage output of the level shifter and thereby decrease a time required to achieve a voltage having a level that causes a state change in a driven circuit. As a result, duty cycle distortion is minimized and maximum operational frequency is increased.