摘要 |
A delay circuit has an input node receives an input pulsed signal. A buffer transfers the input signal to a floating node. A detector outputs to an output node an output voltage that has a first level, if the voltage at the floating node is below a threshold, and a second level otherwise. Two similar branches are used, one for controlling delays in the rising transitions and one for controlling delays in the falling transitions. For each branch, a reference terminal carries a reference voltage for biasing the floating node. A capacitor and a switch are coupled between the reference terminal and the floating node. The switch opens and closes responsive to the output voltage. When it opens, it shorts out the capacitor. An optional phase detector and delay code generator may be in a feedback arrangement, for continuously adjusting the reference voltages.
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