MTJ-Based Temperature Sensing for On-Chip Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional on-chip thermal sensors face challenges such as real estate allocation, high power consumption, and scalability issues when integrated into high-performance integrated circuits, limiting their effectiveness in accurate thermal management and temperature sensing.
Innovation Solution
A temperature-sensing device utilizing magnetic tunnel junction (MTJ) cells with selectable resistance states, integrated into a system circuit as part of an embedded non-volatile memory circuit, which dynamically monitors and estimates on-chip temperatures using temperature-dependent and independent resistance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional diodes are used for temperature sensing, then temperature measurement capability is achieved, but real estate allocation and power consumption increase
Solution Approach 1:
The patent combines temperature sensing functionality with existing diode structures already present in the integrated circuit for other purposes. By utilizing the voltage drop characteristics of these existing diodes across different temperatures, the system achieves temperature measurement without requiring separate dedicated sensor structures, thereby eliminating additional real estate allocation.
Solution Approach 2:
The existing diode structures in the integrated circuit are made to serve dual functions: their primary function and temperature sensing. By measuring the temperature-varying voltage drop across these multi-functional diodes, the system achieves temperature measurement capability while the diodes continue to perform their original circuit functions, avoiding the need for separate dedicated temperature sensors.
2Measurement precision
If conventional diodes are used for temperature sensing, then temperature measurement capability is achieved, but power consumption increases
Solution Approach 1:
The patent combines temperature sensing functionality with existing diode structures already present in the integrated circuit for other purposes. By utilizing the voltage drop characteristics of these existing diodes across different temperatures, the system achieves temperature measurement without requiring separate dedicated sensor structures, thereby eliminating additional real estate allocation.
Solution Approach 2:
The existing diode structures in the integrated circuit are made to serve dual functions: their primary function and temperature sensing. By measuring the temperature-varying voltage drop across these multi-functional diodes, the system achieves temperature measurement capability while the diodes continue to perform their original circuit functions, avoiding the need for separate dedicated temperature sensors.
3Area of stationary object
If MOS transistors are used for temperature sensing, then device size is reduced and power consumption is lowered, but scalability with other on-chip components becomes difficult
Solution Approach 1:
The patent segments the temperature sensing function into discrete measurement points distributed across the integrated circuit substrate. By placing multiple small diodes at different locations and measuring their individual voltage drops, the system achieves both compact size and the ability to map temperature gradients across the chip, improving scalability and adaptability to various on-chip configurations.
Solution Approach 2:
The patent utilizes the temperature-dependent electrical parameters (voltage drop) of diodes to enable temperature sensing. By monitoring changes in these electrical parameters under different temperature conditions, the system achieves accurate temperature measurement while maintaining compatibility with standard integrated circuit fabrication processes and component scaling.
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
The solution provides a lightweight, robust, and power-efficient means for accurate thermal mapping and management, avoiding the limitations of conventional sensors by leveraging MTJ cells' adjustable resistance to estimate temperatures and trigger alarms or optimize power usage.
Implementation Method 1
the first resistance value of the MTJ cell is temperature-independent, and the second resistance value of the MTJ cell is temperature-dependent
Implementation Method 2
The MTJ cell presents a first resistance value when the MTJ cell is in a first state in which a magnetization direction of the free layer is substantially aligned with a magnetization direction of the pinned layer, and the MTJ cell presents a second resistance value when the MTJ cell is in a second state in which the magnetization direction of the free layer is substantially anti-aligned with the magnetization direction of the pinned layer
Data Source
AI summary
A thermometer circuit configured to estimate a monitored temperature is disclosed. The circuit includes an adjustable resistor presenting a first resistance value that is temperature-independent and a second resistance value that is temperature-dependent, wherein a first current signal is conducted across the resistor when it presents the first resistance value and a second current signal is conducted across the resistor when it presents the second resistance value; a plurality of gated conductors coupled to the resistor; and a control circuit, coupled to the resistor and the plurality of gated conductors, and configured to selectively deactivate at least one of the plurality of gated conductors to compare the first and second current signals to estimate the monitored temperature.