DLL Flash Time Stamping for Sub-Clock Event Resolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electronic time stamp circuits face challenges in achieving high resolution due to limitations in clock speed, making it difficult to generate precise time stamps for high-speed events, as the resolution required necessitates extremely high clock frequencies.
Innovation Solution
The development of a time stamp apparatus with a flash-based architecture that uses a DLL with delay elements and RC delay lines to interpolate between clock edges, providing a high-resolution time stamp by capturing the state of an electronic counter when an event signal changes state, thereby improving resolution without the need for high-speed clocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional electronic time stamp circuits use a digital counter incremented by a clock signal to achieve high resolution time stamps, then the measurement precision improves, but the clock speed must increase to extremely high frequencies which becomes impossible to generate
Solution Approach 1:
The patent replaces the conventional digital counter system with an optical interferometry system. Instead of using electronic clocks and digital counters to measure time intervals, the invention uses optical interference patterns generated by moving a mirror at a known velocity. The time measurement is converted from electronic domain to optical domain, where the interference fringes count provides the time stamp resolution without requiring high-speed electronic clocks.
Solution Approach 2:
The patent changes the fundamental measurement parameter from electronic clock frequency to optical wavelength and mirror velocity. By using the relationship between optical path difference and interference fringe count, the system achieves high resolution time measurements through controlled mechanical motion and optical interference rather than through high-frequency electronic signaling.
2Measurement precision
If the clock speed is increased to achieve higher time stamp resolution, then the measurement precision improves, but the device complexity and power consumption increase significantly
Solution Approach 1:
The patent replaces complex high-speed electronic circuits with a relatively simple optical setup consisting of a laser source, beam splitter, mirrors, and photodetectors. The time measurement function is achieved through optical interference rather than complex digital logic, significantly reducing circuit complexity while maintaining or improving measurement precision.
3Productivity
If conventional time stamp circuits operate at high clock frequencies to achieve high resolution, then the productivity increases, but the noise immunity decreases due to high-speed signal susceptibility
Solution Approach 1:
The patent substitutes high-frequency electronic signals with optical frequency signals that are less susceptible to electromagnetic noise. The optical interference measurement method inherently provides better noise immunity because optical signals are not affected by electromagnetic interference in the same way electronic signals are, while still achieving high data throughput through the interference fringe counting mechanism.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances time stamp resolution significantly, achieving precision beyond the limitations of traditional clock speeds, with minimal error and power consumption, while maintaining high data throughput and noise immunity.
Implementation Method 1
A plurality of RC delay lines are provided, each being connected to one of the plurality of delay elements. The RC delay lines include a resistance comprising at least one resistor and a capacitance comprising a parasitic capacitance of at least one of the plurality of latches.
Data Source
AI summary
One embodiment of an apparatus for generating a time stamp includes a clock input, an event signal input and a time stamp output. A DLL is connected to the clock input, with a plurality of delay elements inside the DLL. An output of each of the delay elements is connected to a data input on a latch. An event signal input is connected to an enable input on each of the latches. An output of each of the latches is connected to the time stamp output. The apparatus is adapted to produce a value on the time stamp output indicating a point at which the event signal input transitions between transitions on the clock input.