Symmetric Clock Tree Layout for Precise Divided Signal Phase
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Solution Overview
Problem
Conventional clock tree dividers in integrated circuits produce divided clock signals with significant phase errors, failing to meet the accuracy requirements for signal transmission in semiconductor products.
Innovation Solution
A clock tree layout is designed with a divider module, phase modules symmetrically distributed in a preset direction, and a wire pattern layer to connect them, ensuring a precise phase difference between clock signals within a preset range, thereby reducing phase errors and improving signal consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a conventional divider divides the input clock signal, then the clock signal can be divided into multiple signals, but large phase errors occur in the divided clock signals
Solution Approach 1:
The clock tree is divided into multiple symmetric branches, with phase modules symmetrically distributed around the divider module. Each branch is designed to have equal length and equivalent electrical characteristics, segmenting the clock distribution into balanced paths that maintain phase accuracy while providing multiple divided clock signals.
Solution Approach 2:
The patent employs symmetric layout design where phase modules are positioned at equal distances from the divider module in opposite directions. This symmetric arrangement ensures that signal paths have equal length and impedance, eliminating phase differences between divided clock signals by making the previously asymmetric conventional layout symmetric.
2Measurement precision
If phase modules are added to reduce phase errors, then phase accuracy improves, but circuit complexity increases
Solution Approach 1:
The symmetric layout design serves multiple functions simultaneously: it equalizes signal path lengths, balances impedance characteristics, provides physical isolation between clock domains, and establishes a scalable template for additional phase modules. This multi-functionality achieves phase accuracy without proportionally increasing complexity.
Solution Approach 2:
The clock tree structure is designed with nested symmetry, where phase modules are positioned at hierarchical levels equidistant from the divider. This nested symmetric arrangement allows the circuit to scale while maintaining phase accuracy, as additional modules can be added in symmetric pairs without disrupting the balanced structure.
Data Source
AI summary
The present disclosure relates to a clock tree layout and a forming method thereof. The clock tree layout includes: a divider module layout, a phase module layout and a wire pattern layer. The divider module layout is configured to receive a first clock signal, and divide the first clock signal, and obtain a plurality of second clock sampling signals phase-associated; the phase module layout includes a first quantity of phase modules disposed in a first preset direction, the phase module is configured to generate a second clock signal based on a correspondingly connected second clock sampling signal, and the phase modules are symmetrically distributed with respect to the divider module layout; the wire pattern layer is configured to electrically connect the phase module and a divider module in the divider module layout; a difference between phases of any two of the second clock signals falls within a preset precision range.