Level shifter control circuit with delayed switchover to low-power level shifter

摘要

A level shifter control circuit selects one of two level shifters for converting a signal output from a circuit operating on a first power supply for input to a circuit operating on a second power supply. A low-power level shifter is selected when the difference between the two power-supply potentials is comparatively small. A wide-range level shifter is selected when the difference is greater. The switchover from the wide-range level shifter to the low-power level shifter is delayed to allow the power-supply potential difference to diminish to within the operating range of the low-power level shifter, thereby avoiding gaps in the level-shifted signal.