Power Semiconductor Temperature Measurement Using Diode VF Coefficient
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The accuracy of temperature measurement in power semiconductor devices is compromised due to the wide variation in forward voltage (VF) of temperature detection diodes, especially across a wide temperature range, leading to a reduced operational margin and increased risk of device failure.
Innovation Solution
An electronics device comprising a power semiconductor device, a drive circuit, and a control unit that utilizes a temperature detection diode to measure chip temperature by acquiring outside air temperature information and using stored temperature characteristic data to calculate the temperature of the semiconductor device, thereby improving measurement accuracy and expanding the operational margin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If temperature measurement is performed using a temperature detection diode in a wide temperature range, then the operational range is extended, but measurement accuracy is reduced due to wide variation in forward voltage
Solution Approach 1:
The patent changes the measurement parameter from direct forward voltage measurement to temperature coefficient measurement. By measuring the rate of change of forward voltage with temperature (dVF/dT) rather than the absolute forward voltage value, the system achieves accurate temperature measurement across a wide temperature range despite variations in absolute VF values among different diodes.
Solution Approach 2:
The patent replaces the conventional method of temperature measurement (direct VF measurement at known temperature points) with a differential measurement approach. Instead of measuring absolute voltage values and comparing them to reference tables, the system measures the temperature coefficient by applying small AC test signals and detecting the rate of change, which is more robust to manufacturing variations.
2Measurement precision
If the forward voltage variation of the temperature detection diode is considered, then measurement accuracy improves, but the device complexity increases due to additional measurement circuits
Solution Approach 1:
The patent introduces an intermediary measurement approach by using AC test signals and a transimpedance amplifier to convert the small voltage changes in the diode into measurable current signals. This intermediary conversion process enables accurate measurement of the temperature coefficient without requiring complex direct voltage measurement circuits.
Solution Approach 2:
The patent employs periodic AC test signals to measure the temperature coefficient. By applying sinusoidal test voltages at a specific frequency and measuring the resulting current response, the system can extract the temperature coefficient through frequency-domain analysis, which simplifies the measurement circuit compared to continuous DC measurement approaches.
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 solution enhances temperature measurement accuracy and extends the operational range of power semiconductor devices, reducing the likelihood of failure by accurately determining the temperature and adjusting the drive circuit accordingly.
Implementation Method 1
Temperature measurement of a semiconductor chip is performed by utilizing temperature dependency of a forward voltage (VF) of a diode which is installed in the semiconductor chip.
Data Source
AI summary
An electronics device includes a power semiconductor device including a temperature detection diode, a first semiconductor integrated circuit device including a detection circuit for detecting VF from the temperature detection diode and a second semiconductor integrated circuit device. The second semiconductor integrated circuit device includes, an outside air temperature acquisition unit which acquires outside air temperature information, a storage which stores temperature characteristic data of the temperature detection diode and a first value based on a signal from the detection circuit at a first temperature and a temperature arithmetic processing unit which calculates a temperature of the power semiconductor device from a third value based on a signal from the detection circuit, the temperature characteristic data, the first temperature acquired by the outside air temperature acquisition unit and the first value.