System for automatically selecting intermediate power supply voltages for intermediate level shifters

Abstract

The present invention provides for a system comprising a level shifter configured to receive a first clock signal from a first power domain, to receive a counter signal, to select one of a plurality of intermediate voltages in response to the received counter signal, and to generate a second clock signal in response to the received first clock signal and the selected intermediate voltage. A counter is coupled to the level shifter and configured to receive a divided clock signal and a comparison result signal, and to generate the counter signal in response to the received divided clock signal and comparison result signal. A divider is coupled to the counter and configured to receive the first clock signal and to generate the divided clock signal in response to the received first clock signal. A filter is coupled to the level shifter and configured to receive the second clock signal and to generate a first comparison signal in response to the received second clock signal. A fixed potential is configured to generate a second comparison signal. A comparator is coupled to the filter, the fixed potential, and the counter and configured to receive the first comparison signal and the second comparison signal, and to generate the comparison result signal in response to the received first comparison signal and the second comparison signal.