Timing Generator With Edge Masking for Arbitrary Pulse Widths

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Solution Overview

Problem

Existing timing generators for depth-imaging devices, particularly in time-of-flight (TOF) sensing, face challenges in achieving high resolution for pulse widths and precise placement of rising and falling edges of timing signals, which is crucial for accurate distance measurement and three-dimensional imaging applications.

Innovation Solution

A timing generator system comprising a coarse delay circuit, a fine delay circuit, an edge combiner, and a masking circuit, which allows for the generation of timing signals with rising and falling edges placed with a resolution finer than a clock period, achieving pulse widths less than and greater than the clock period, and enabling arbitrary pulse widths by controlling the clock period through masking mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional timing generator uses a single delay circuit operated at a fixed clock period, then the device complexity is low, but the timing resolution cannot be finer than the clock period and pulse widths cannot be arbitrarily controlled

Engineering Contradiction:
Improvetiming resolutionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The timing generator is divided into multiple independent delay circuits (first delay circuit, second delay circuit, third delay circuit, fourth delay circuit) each operating at different clock periods. This segmentation allows each circuit to contribute differently to the final timing signal, enabling resolution finer than any single clock period while maintaining manageable complexity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multiple delay circuits serve multiple functions: they generate timing signals at different resolutions, provide arbitrary pulse width control through selective combination, and enable both rising and falling edge manipulation. This multi-functionality achieves high timing resolution without proportionally increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If the clock period is reduced to achieve finer timing resolution, then the timing resolution improves, but the pulse width control becomes limited and cannot achieve arbitrary widths

Engineering Contradiction:
Improvetiming resolutionVSAvoidpulse width adaptability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system dynamically selects and combines timing signals from different delay circuits based on desired pulse width requirements. The edge combiner circuit dynamically adjusts which rising and falling edges are combined, allowing arbitrary pulse widths to be constructed from finer resolution timing components, thus achieving both high resolution and adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the effective clock period parameter by selectively combining signals from circuits operating at different clock periods. This allows the output to achieve timing resolution finer than any individual clock period while maintaining the ability to generate arbitrary pulse widths through parameter manipulation.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple delay circuits operating at different clock periods are used to achieve high resolution and arbitrary pulse widths, then the timing resolution and adaptability improve, but the device complexity increases

Engineering Contradiction:
Improvetiming resolutionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple timing signals from different delay circuits are merged by the edge combiner circuit. This combining approach allows the system to achieve high timing resolution and arbitrary pulse width control by synthesizing the strengths of multiple circuits, while the merging process itself is implemented through standard logic circuitry that minimizes additional complexity.

Inventive Principle:
Principle #5Merging (Combining)

4Adaptability or versatility

If the rising edge and falling edge are controlled independently to achieve arbitrary pulse widths, then the adaptability improves, but the device complexity increases due to separate control mechanisms

Engineering Contradiction:
Improvepulse width control flexibilityVSAvoidcontrol circuit complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The control of rising and falling edges is segmented into separate delay circuits (first and second for rising edges, third and fourth for falling edges). This segmentation allows independent manipulation of each edge while using identical circuit architectures, achieving high control flexibility without proportionally increasing overall complexity through repetition of proven designs.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3427381B1Timing generator for generating high resolution pulses having arbitrary widths
Publication Date: 2024.05.01 ANALOG DEVICES INC
  • EP3427381B1 patent drawingFigure 1
  • EP3427381B1 patent drawingFigure 2~3
  • EP3427381B1 patent drawingFigure 4

AI summary

An exemplary timing generator includes a coarse delay circuit configured to generate a coarse delayed rising edge signal and a coarse delayed falling edge signal from a reference timing signal; a fine delay circuit configured to generate a fine delayed rising edge signal from the coarse delayed rising edge signal and a fine delayed falling edge signal from the coarse delayed falling edge signal; an edge combiner configured to generate the timing signal based on the fine delayed rising edge signal and the fine delayed falling edge signal; and a masking circuit configured to generate a rising edge masking signal and a falling edge masking signal for controlling when the rising edges and the falling edges of the timing signal are generated.