Patent ID: 6920570
Filing Date: 2005-07-19
Classification: G06F,H03K

Abstract:
1. A method of selecting one of a first level shifter and a second level shifter to convert a signal compatible with a first power-supply potential to a signal compatible with a second power-supply potential, the first level shifter consuming less power than the second level shifter, the method comprising: receiving a selection signal, changes in the selection signal being accompanied by changes in the second power-supply potential; switching from the first level shifter to the second level shifter when the selection signal changes from a first level to a second level; setting a delayed selection signal to the second level while the selection signal is at the second level, before the second power-supply potential begins to change; setting the delayed selection signal to the first level after the selection signal has changed to the first level and the second power-supply potential has begun to change; and selecting the first level shifter according to the delayed selection signal.