Termination Circuit With Code-Modified Impedance Matching

Solution Overview

Problem

Conventional impedance matching circuits for semiconductor devices require multiple termination impedance units, increasing circuit area and leading to performance degradation due to large capacitance components at the interface pad, which complicates high-speed data transmission and introduces signal distortion.

Innovation Solution

A termination circuit that generates various termination impedances using a calibration circuit and a code modification unit to modify impedance calibration codes, allowing a single termination impedance unit to support multiple impedance settings, thereby reducing the number of units needed and minimizing circuit area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple termination impedance units are used to provide various termination impedances, then impedance matching capability is improved, but circuit area increases and capacitance at interface pad increases

Engineering Contradiction:

Improveimpedance matching capabilityVSAvoidcircuit area

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

A single termination impedance unit is designed to perform multiple functions by switching between different impedance values (40Ω, 60Ω, 120Ω) based on calibration codes, eliminating the need for multiple dedicated impedance units and reducing circuit area

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The termination impedance value is dynamically changed by switching between different resistor configurations (R1, R2, R3) based on calibration codes, allowing a single unit to provide multiple impedance settings instead of requiring separate units for each impedance value

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If multiple termination impedance units are used to provide various termination impedances, then impedance matching capability is improved, but capacitance at interface pad increases causing performance degradation

Engineering Contradiction:

Improveimpedance matching capabilityVSAvoidcapacitance at interface pad

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

A single termination impedance unit is designed to perform multiple functions by switching between different impedance values (40Ω, 60Ω, 120Ω) based on calibration codes, eliminating the need for multiple dedicated impedance units and reducing circuit area

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The harmful capacitance effect is reduced by removing redundant impedance units from the circuit, keeping only the essential single termination impedance unit that can be switched to provide various impedance values, thereby extracting the unnecessary capacitance sources

Inventive Principle:

Principle #2Taking out (Extraction)

3Adaptability or versatility

If multiple termination impedance units are used, then various termination impedances can be provided, but device complexity increases

Engineering Contradiction:

Improvetermination impedance optionsVSAvoidnumber of termination impedance units

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

A single termination impedance unit is designed to perform multiple functions by switching between different impedance values (40Ω, 60Ω, 120Ω) based on calibration codes, eliminating the need for multiple dedicated impedance units and reducing circuit area

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The termination impedance unit employs dynamic switching between different resistor configurations (R1, R2, R3) controlled by calibration codes, allowing the impedance value to be adjusted as needed rather than requiring static multiple units for each possible impedance value

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS7893710B2Termination circuit and impedance matching device including the same

Publication Date: 2011.02.22 SK HYNIX INC

AI summary

An impedance matching device includes a calibration circuit configured to generate impedance calibration codes for modification of impedance; a code modification unit configured to modify the impedance calibration codes according to impedance setting information and output modified impedance calibration codes; and a termination impedance unit configured to terminate an interface node with impedance determined according to the modified impedance calibration codes.