Patent ID: 7425857

Claim:
A time-delay circuit, comprising an input terminal and an output terminal; a first stage having: a first inverter having a switching threshold voltage; a first capacitor coupled to an input terminal of the first inverter; and means for controlling a charge of the first capacitor capable of responding to a predetermined edge of a input pulse applied to the input terminal of the circuit by bringing the input terminal of the first inverter from a first predetermined voltage to the switching threshold voltage and obtaining on an output terminal of the first inverter a pulse having an edge that, as referred to the predetermined edge of the input pulse, has a first delay time; a second stage electrically complementary to the first stage and having: an input terminal and an output terminal coupled to the output terminal of the circuit; a second inverter having a switching threshold voltage substantially equal to that of the first inverter and an output terminal that is the output terminal of the stage; a second capacitor coupled to an input terminal of the second inverter; and means for controlling a charge of the second capacitor capable of responding to the edge of the pulse present on the output terminal of the first inverter by bringing the input terminal of the second inverter from a second predetermined voltage to the switching threshold voltage and obtaining on the output terminal of the second inverter a pulse having an edge that, as referred to the edge of the output pulse of the first inverter, has a second delay time, an overall delay of the circuit being a sum of the first and the second delay time; and a third inverter coupled between the output terminal of the first inverter and the input terminal of the second inverter, wherein the means for controlling the charge of the first capacitor comprise a first constant current generator and a first controlled electronic switch connected in series with each other between a first and a second supply terminal of the circuit, said first controlled electronic switch having a control terminal connected to the input terminal of the circuit; and the means for controlling the charge of the second capacitor comprise a second constant current generator and a second controlled electronic switch connected in series with each other between the second and the first supply terminal, said second controlled electronic switch having its control terminal connected to the output terminal of the third inverter.