Patent ID: 6870413

Claim:
A Schmitt trigger circuit comprising: a first transistor coupled between a reference node and a first node, a second transistor coupled between the first node and a second node, a third transistor coupled between the second node and a third node, and a fourth transistor coupled between the third node and a power supply node, each of the first, second, third, and fourth transistors having a control terminal for receiving an input signal; a first plurality of circuits for selectively providing a path between the first node and the power supply signal node, each circuit in the first plurality of circuits comprising a fifth transistor and a sixth transistor, the fifth transistor having a control terminal coupled to the second node and the fifth transistor being coupled between the power supply signal node and the sixth transistor, the sixth transistor having a control terminal for receiving a control signal provided to said circuit and the sixth transistor being coupled between the fifth transistor and the first node, wherein each of said circuits is controlled by a control signal so that only one of the first plurality of circuits provides the path between the first node and the power supply signal node at any one time; a second plurality of circuits for selectively providing a path between the third node and the reference node, each circuit in the second plurality of circuits comprising a seventh transistor and an eighth transistor, the seventh transistor having a control terminal coupled to the second node and the seventh transistor being coupled between the reference node and the eighth transistor, the eighth transistor having a control terminal for receiving a control signal provided to said circuit and the eighth transistor being coupled between the seventh transistor and the third node, wherein each of said circuits is controlled by a control signal so that only one of the second plurality of circuits provides the path between the third node and the reference node at any one time.