Quadratic Thermal Model for Hotspot Interpolation

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Solution Overview

Problem

Conventional temperature management systems face challenges in accurately estimating hotspot temperatures on chips without interfering with chip design and performance, as thermal sensors placed near hotspots can disrupt operations and require significant margins to account for measurement errors, leading to unnecessary performance reductions.

Innovation Solution

A temperature management system that uses multiple thermal sensors placed away from hotspots to fit a quadratic temperature model, allowing for accurate estimation of hotspot temperatures without the need for sensors at the hotspot location, thereby reducing unnecessary performance throttling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If thermal sensors are placed near hotspots to accurately measure temperature, then measurement precision is improved, but chip performance deteriorates due to interference with operations and unnecessary performance throttling

Engineering Contradiction:
Improvehotspot temperature measurement precisionVSAvoidchip performance
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent uses an interpolation algorithm as an intermediary to estimate hotspot temperature indirectly through readings from surrounding sensors, rather than placing sensors directly at the hotspot location. This mediator approach allows accurate temperature estimation without physical sensors interfering with chip operations at critical locations

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a thermal model that copies the thermal characteristics of the chip by using temperature readings from multiple sensors around the hotspot to reconstruct the temperature distribution. This virtual copy allows accurate hotspot temperature estimation without requiring physical sensors at the hotspot location

Inventive Principle:
Principle #26Copying

2Productivity

If thermal sensors are placed away from hotspots to avoid interference, then chip performance is improved, but measurement precision deteriorates due to increased margin for error

Engineering Contradiction:
Improvechip performanceVSAvoidhotspot temperature measurement precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent divides the chip into multiple regions with sensors placed at strategic locations away from the hotspot, then uses interpolation to reconstruct the complete temperature field. This segmentation allows sensors to be positioned in non-critical areas while still capturing sufficient information for accurate hotspot temperature estimation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from direct one-point measurement to multi-point spatial measurement by using temperature readings from multiple sensors distributed across the chip. This dimensional approach allows accurate hotspot temperature estimation through spatial interpolation even when individual sensors are positioned away from the hotspot

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If sensors are placed at hotspot location to minimize measurement error, then measurement precision is improved, but device complexity increases due to sensor placement constraints and design interference

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidsensor placement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the temperature sensing function from the hotspot location itself and relocates it to surrounding areas. By taking out the sensor placement requirement from the critical hotspot zone and using computational methods instead, the design complexity at the hotspot location is reduced while maintaining measurement accuracy

Inventive Principle:
Principle #2Taking out (Extraction)

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 enables precise hotspot temperature estimation and reduces the margin for error, allowing chips to operate at higher speeds for longer periods before thermal mitigation is initiated, thereby improving performance and reducing the risk of thermal runaway.

Implementation Method 1

a plurality of thermal sensors at different locations on a chip

Methodology Applied
Scientific EffectThermal detection: Thermistor

Implementation Method 2

fit a quadratic temperature model to the received temperature readings, and to estimate a hotspot temperature on the chip using the fitted quadratic temperature model

Methodology Applied
Scientific EffectTemperature interpolation:

Data Source

PatentEP3347819B1Thermal sensor placement for hotspot interpolation
Publication Date: 2020.01.08 QUALCOMM INC
  • EP3347819B1 patent drawingFigure 1
  • EP3347819B1 patent drawingFigure 2
  • EP3347819B1 patent drawingFigure 3

AI summary

In one embodiment, a temperature management system comprises a plurality of thermal sensors at different locations on a chip, and a temperature manager. The temperature manager is configured to receive a plurality of temperature readings from the thermal sensors, to fit a quadratic temperature model to the received temperature readings, and to estimate a hotspot temperature on the chip using the fitted quadratic temperature model.