Patent ID: 6624680
Filing Date: 2003-09-23
Classification: H03K

Abstract:
A digital circuit element having a propagation delay that is substantially constant over a range of supply voltages applied to the digital circuit element, comprising:an input node; an output node; and at least one gate coupling the input node and the output node, said gate powered by a voltage source which may vary over the range of supply voltages, there being a plurality of possible voltage transition curves over the range of supply voltages associated with a corresponding change of a first voltage at the input node over time and each voltage transition curve being determined by a corresponding supply voltage, the voltage transition curves intersecting within a relatively narrow range of voltages, the gate operable to change a second voltage at the output node in response to the first voltage reaching a threshold voltage of the gate, the threshold voltage of the gate being set within the relatively narrow range of voltages in which the voltage transition curves intersect in order to reduce the dependence of the propagation delay on the supply voltage.