Method and apparatus for tuning delay

Abstract

Aspects of the disclosure provide a fine tunable digital delay circuit that can be applied in a high frequency digital circuit. Further, the digital delay circuit can utilize a level restoring technique to enable a wide tunable delay range. The delay circuit can include a delay element configured to receive an input signal at an input node and output a controlled signal having a controlled rise time and a controlled fall time at a controlled node, a first plurality of transistors configured to bias a supply node of the delay element to govern the controlled rise time of the controlled signal, and a second plurality of transistors configured to bias a ground node of the delay element to govern the controlled fall time of the controlled signal. The delay circuit can further include a restoring circuit configured to charge or discharge the controlled node.

Dependencies are inferred from the claim text.