Patent ID: 7190206

Claim:
A level-down shifter comprising: a first circuit unit having an input and an output and being connected to a first power node, the first circuit unit has its input connected to a first node and receives an input signal that swings from ground to a first voltage level and has its output connected to a second node; a second circuit unit having an input and an output and being connected to a second power node, the second circuit unit has its input connected to the second node and receives the output of the first circuit unit; a third circuit unit having an input and an output and being connected to the second power node, the third circuit unit has its input connected to the first node and receives at its input the in put signal and has its output connected to a third node; and a fourth circuit unit having an input and an output and being connected to the second power node, the fourth circuit unit has its input connected to the third node and receives the output of the third circuit unit and has its output connected to the output of the second circuit unit at a fourth node.