Apparatus for controllable delay cell and associated methods
AssigneeAltera Corporation
InventorJeffrey Christopher Chromczak
Life of this patent
Estimating the term…
Abstract
A delay cell includes a feed-forward inverter and a feedback inverter. The feedback inverter is coupled to the feed-forward inverter. The feed-forward inverter has an input and an output. Similarly, the feedback inverter has an input and an output. A drive strength of the feed-forward inverter is larger than a drive strength of the feedback inverter such that a transition at the input of the feed-forward inverter propagates to the output of the feed-forward inverter.
Claims18
A delay cell, comprising:
- a feed-forward inverter having an input and an output;
- and
- a feedback inverter, having an input and an output, coupled to the feed-forward inverter,
- wherein a drive strength of the feed-forward inverter is larger than a drive strength of the feedback inverter such that a transition at the input of the feed-forward inverter propagates to the output of the feed-forward inverter, and
- wherein respective sensitivities of the feed-forward and feedback inverters are selected such that a sensitivity of the delay cell has a desired value.
A delay chain circuit, comprising a plurality of delay cells coupled in cascade, each delay cell having a feed-forward path and a feedback path, wherein a drive strength of the feed-forward path is larger than a drive strength of the feedback path such that a transition at an input of the respective delay cell propagates to an output of the delay cell, and wherein the drive strength of a feed-forward path and/or a feedback path in at least one delay cell is adjusted so that a delay of the delay chain is supply voltage insensitive.
A method of delaying a signal by a desired delay, the method comprising:
- feeding the signal to an input of a feed-forward path to generate an output signal;
- and
- feeding back the output signal through a feedback path to the input of the feed-forward path,
- wherein drive strengths and/or sensitivities of the feed-forward and feedback paths are adjusted such that the delay has a desired sensitivity to a quantity.
Dependencies are inferred from the claim text.