Variable Resistor Code Mapping for Even Resistance Steps

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Solution Overview

Problem

Existing variable resistors often have unevenly spaced discrete resistance values, leading to undesirable intervals between consecutive resistance levels, especially at large and small resistance levels.

Innovation Solution

A variable resistance apparatus using PMOS and NMOS-based components with variable resistors that implement a binary code mapping scheme to translate 4-bit binary codes into 5-bit codes, allowing for the adjustment of transistors in parallel combinations to achieve substantially even intervals between resistance levels, enabling precise calibration to target resistance values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If discrete variable resistors are used to provide multiple resistance values, then resistance adjustment capability is improved, but the spacing between consecutive resistance values becomes uneven

Engineering Contradiction:

Improveresistance adjustment capabilityVSAvoidspacing uniformity of resistance values

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by making the resistor configuration adjustable through transistor control. The variable resistor's resistance value can be dynamically changed by activating or deactivating parallel resistive paths controlled by transistor gates, allowing continuous adaptation between different resistance states rather than fixed discrete values.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent segments the variable resistor into multiple parallel resistive paths (first and second resistors) that can be independently controlled. This segmentation allows the total resistance to be divided into manageable portions that can be selectively activated, enabling precise control over the resistance value and achieving more uniform spacing between consecutive resistance levels.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If variable resistors provide multiple discrete resistance values, then resistance selection range is improved, but intervals between consecutive values become undesirable at extreme levels

Engineering Contradiction:

Improveresistance selection rangeVSAvoidinterval uniformity at extreme resistance levels

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the resistance parameter by utilizing transistor gate voltage control to adjust the effective resistance of the variable resistor. By varying the gate voltage, the resistance can be continuously adjusted across a wide range, and the parallel resistor configuration ensures that even at extreme resistance levels, the intervals between consecutive values remain relatively uniform through the selective activation of different parallel paths.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If transistor-based variable resistance logic is used, then resistance calibration precision is improved, but device complexity increases

Engineering Contradiction:

Improveresistance calibration precisionVSAvoidtransistor and logic circuit complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies universality by designing the transistor-based variable resistance logic to serve multiple functions. The same transistor configuration and control logic can be used across different resistance calibration scenarios, and the parallel resistor structure allows the system to function across a wide resistance range while maintaining uniform intervals, reducing the need for multiple separate calibration circuits.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 allows for more accurate calibration of resistors to target resistance levels, reducing the difference between actual and desired resistance values, and ensuring even spacing of resistance intervals, thereby improving the precision and reliability of resistance adjustments.

Implementation Method 1

Referred to as 'variable resistors,' these types of resistors may be adjusted to provide greater or less resistance to current that passes through the resistors

Methodology Applied

Scientific EffectTransistor operation:

Data Source

PatentUS7511644B2Variable resistance logic

Publication Date: 2009.03.31 MICRON TECHNOLOGY INC

AI summary

A system comprising a control logic that generates a code having n digits, a translation logic coupled to the control logic that translates the code to a new code having greater than n digits, and a variable resistance logic coupled to the translation logic and comprising greater than n semiconductor devices. A resistance associated with the variable resistance logic depends on activation statuses of the semiconductor devices. The translation logic adjusts at least some of the semiconductor devices in accordance with the new code.