Programmable Delay Circuit With Reused Delay Chain Elements
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional programmable delay lines face issues with high power consumption, large area usage, and increased leakage power due to the need for a large number of delay elements, which also leads to predictability problems from process variations and non-monotonicity in delay selection.
Innovation Solution
A programmable delay line design utilizing a limited number of series-connected delay elements, where the delay chain is controlled by a pulse generator and a multiplexer-based delay chain control circuit, allowing for the reuse of delay units to produce longer delays without increasing the number of elements, thereby reducing circuitry and improving stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a large number of delay elements are used to achieve substantial reference or absolute delays, then the delay range is improved, but leakage power and static power consumption increase significantly
Solution Approach 1:
Each delay element in the chain serves multiple functions: it provides delay for the current position in the chain, and its output serves as the input for the next delay element. This multi-functional arrangement allows a limited number of delay elements to produce a large number of different delay values through selective tapping at intermediate points, eliminating the need for a large number of separate delay elements.
Solution Approach 2:
The patent transitions from a one-dimensional approach (using many delay elements in parallel) to a two-dimensional approach (using a sequence of delay elements where each element's output feeds the next). This dimensional change allows the system to generate multiple delay values from a limited number of elements by utilizing the temporal sequence of signal propagation through the chain.
2Duration of action of moving object
If a large number of delay elements are used to achieve substantial reference or absolute delays, then the delay range is improved, but the area usage increases
Solution Approach 1:
Each delay element in the chain serves multiple functions: it provides delay for the current position in the chain, and its output serves as the input for the next delay element. This multi-functional arrangement allows a limited number of delay elements to produce a large number of different delay values through selective tapping at intermediate points, eliminating the need for a large number of separate delay elements.
3Duration of action of moving object
If a large number of delay elements are used to achieve substantial reference or absolute delays, then the delay range is improved, but delay predictability decreases due to process variations
Solution Approach 1:
The patent uses a limited number of delay elements (exactly enough to provide the desired delay range) rather than an excessive number of elements. By using only the necessary number of delay elements and selectively tapping at intermediate points, the system achieves the required delay range while minimizing the cumulative effect of process variations on delay predictability.
4Stability of the object's composition
If buffer-based delay elements are used with sharp transitions to reduce jitter and process sensitivity, then delay uniformity is improved, but dynamic power dissipation increases
Solution Approach 1:
The patent uses buffer-based delay elements with sharp transitions only where necessary to maintain delay uniformity and reduce jitter, rather than applying them excessively throughout the entire delay chain. By selectively using sharp-transition buffers only at critical points and using simpler delay elements elsewhere, the system achieves adequate delay uniformity while minimizing dynamic power dissipation.
Data Source
AI summary
A delay line includes a delay chain, a pulse generator generating a pulse based on a received input signal, and a delay chain control circuit. The delay chain control circuit has a first input receiving the pulse, a second input receiving output from a last element of the delay chain, and a selection input receiving a delayed version of the received input signal. The delay chain control circuit has an output coupled to provide input to a first element of the delay chain in response to the delayed version of the received input signal. An output selection circuit receives outputs from each element of the delay chain, counts assertions of the output of the last element of the delay chain and, in response to the count being equal to a desired count, passes a desired one of the outputs of the elements of the delay chain as output.