On-Chip Temperature Sensor Calibration Using Local Micro-Heaters
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Solution Overview
Problem
Existing temperature sensors on integrated circuits are not compact enough and require accurate calibration at multiple temperatures, which is costly and impractical with current methods.
Innovation Solution
A method for temperature sensing using a temperature sensor circuit with on-chip calibration heaters that generate precise local temperature increases, allowing accurate temperature determination at a single test temperature, independent of the Temperature Management Controller (TMC) temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional temperature sensors are used on integrated circuits, then temperature sensing capability is provided, but the sensor size is too large and requires multi-temperature calibration which is costly and impractical
Solution Approach 1:
The patent changes the calibration approach by using a micro-heater to dynamically adjust the local temperature around the sensor during a single test temperature calibration. By applying controlled heating and measuring the sensor response at different temperature points achieved through the heater, the system achieves multi-temperature calibration performance without requiring actual multi-temperature testing environments.
Solution Approach 2:
The micro-heater acts as an intermediary device that creates a controlled thermal environment around the temperature sensor. Instead of requiring external multi-temperature testing equipment, the heater mediates the calibration process by locally modifying the temperature conditions, allowing the sensor to be calibrated across a temperature range while the system operates at a single ambient temperature.
2Reliability
If temperature sensors are placed at tight spacing to capture hot spots, then temperature monitoring coverage is improved, but the sensor area increases which degrades electrical performance of protected circuits
Solution Approach 1:
The patent segments the temperature sensing function into a compact integrated structure that combines the temperature sensor, micro-heater, and calibration control circuitry into a single small-footprint module. This segmentation allows multiple sensors to be placed at tight spacing across the die without each sensor occupying excessive area that would interfere with the circuits being protected.
Solution Approach 2:
The temperature sensor design incorporates multiple functions within a single compact structure: temperature sensing, self-heating for calibration, and control logic. This multi-functionality eliminates the need for separate calibration equipment and reduces the overall area required for each sensing node, enabling dense placement while maintaining reliability.
3Measurement precision
If multi-temperature calibration is performed for accurate temperature sensing, then measurement precision is improved, but testing cost and practicality deteriorate
Solution Approach 1:
The temperature sensor system performs its own calibration using an integrated micro-heater and control circuitry. During calibration mode, the system automatically applies controlled heating through the micro-heater, measures the sensor response at different temperature points, and stores the calibration data without requiring external multi-temperature testing equipment. This self-service approach dramatically reduces calibration cost and complexity while maintaining high measurement precision.
Solution Approach 2:
The calibration process is performed preliminarily during manufacturing or initialization using the micro-heater to create controlled temperature conditions. By pre-calibrating the sensor across a temperature range using the heater before actual operation, the system eliminates the need for costly post-manufacturing multi-temperature testing and ensures accurate temperature measurement throughout the device lifecycle.
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
Enables compact temperature sensors with accurate calibration performance comparable to multi-temperature measurements, reducing testing costs and ensuring reliable temperature sensing across the integrated circuit.
Implementation Method 1
A method of calibration of temperature sensors is disclosed that will allow for single-temperature calibration with performance comparable to that obtained with multi-temperature measurements. This approach uses an on-chip heater to rapidly generate one or more internal temperatures
Data Source
AI summary
Various embodiments disclosed herein provide for an improved method for sensing the temperature at an individual sensor location that is both small in size, and the temperature can be determined independent of the temperature of the Temperature Management Controller (TMC). The method includes determining the temperature at the temperature sensing element or circuit based on a function of two voltages measured at the temperature sensing element. In a first embodiment, the two voltages are measured at two transistors that are each being supplied with the same current. In another embodiment, the temperature sensing element includes a single transistor that is supplied with two different currents at different times, and the voltages are measured at the same current, with each of the two voltages being measured based on the two currents being supplied to the transistor.