Miniaturized Thermistor Sensor for Multi-Core Thermal Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated thermal sensors in microprocessors and other integrated circuits face challenges with increased thermal dissipation, reduced chip dimensions, and the need for accurate temperature measurement across multiple hot-spots, requiring smaller, lower power consumption sensors with high resolution and fast conversion times, while existing resistor-based sensors struggle with area reduction and energy efficiency.
Innovation Solution
A novel resistor-based thermal sensor design implemented in 65 nm CMOS technology, achieving a reduced area of 10,000 μm², with an 80 μs conversion time and 0.9 nJ energy consumption, utilizing a folded-cascode amplifier and dynamic biasing circuit to maximize sensitivity and minimize errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of thermal sensors is increased to detect multiple hot-spots in multi-core processors, then temperature monitoring coverage is improved, but the total area and power consumption of sensors increase
Solution Approach 1:
The patent divides the thermal sensing function into multiple independent miniaturized sensors distributed across different cores and hot-spot locations. Each sensor is a separate unit with area of 10,000 μm², allowing independent placement to monitor specific hot-spots without requiring large contiguous sensor areas.
2Measurement precision
If the number of thermal sensors is increased to detect multiple hot-spots in multi-core processors, then temperature monitoring coverage is improved, but the total power consumption of sensors increases
Solution Approach 1:
The thermal sensing function is segmented into multiple low-power independent sensors, each consuming only 0.9 nJ per conversion. This segmentation allows the system to achieve comprehensive temperature monitoring coverage across multi-core processors while keeping the power consumption of each individual sensor and the total power budget manageable.
3Productivity
If chip dimensions are reduced to increase integration density, then device integration is improved, but thermal dissipation becomes more difficult and sensor area reduction is required
Solution Approach 1:
The patent implements thermal sensors in the vertical dimension by integrating them within the CMOS device stack rather than only in the planar dimension. The sensors utilize the third dimension (depth) by implementing thermistors through multiple metal layers and vias, allowing thermal monitoring without increasing the chip footprint and enabling better thermal management in highly integrated 3D structures.
4Productivity
If sensor area is reduced to increase integration density, then device integration is improved, but measurement precision and sensitivity may deteriorate
Solution Approach 1:
The patent changes the physical parameters of the thermistor by utilizing the temperature coefficient of resistivity (TCR) effect in semiconductor materials. By carefully selecting and engineering the TCR parameter of the thermistor material and structure, the sensor achieves high measurement precision and sensitivity despite the reduced area of 10,000 μm², maintaining accurate temperature detection capability in a compact form factor.
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 sensor achieves one of the smallest and lowest energy consumption levels among thermistor sensors, with competitive resolution and fast sample time, suitable for CPU applications, and is insensitive to clock jitter, effectively addressing the challenges of thermal management in integrated circuits.
Implementation Method 1
The temperature coefficient of resistivity (TCR) is nearly constant and several different types of resistors are available in CMOS
Implementation Method 2
utilizing a folded-cascode amplifier and dynamic biasing circuit to maximize sensitivity and minimize errors
Data Source
AI summary
A thermal sensor includes a first resistor and a first capacitor. The first resistor is a thermistor. A first current source is coupled to the first resistor and the first capacitor. The first current source alternately charges the first resistor and the first capacitor each to a reference voltage, Vtherm. An output of the thermal sensor is a function of a resistance-capacitance (RC) time constant of the first resistor and the first capacitor.