Semiconductor Device Temperature Detection Using Hysteresis Comparators
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Solution Overview
Problem
Existing semiconductor devices using power semiconductor switching elements, such as IGBTs, face challenges in accurately detecting the temperature of individual elements and efficiently collecting temperature information due to variations in output voltages from temperature detection diodes, leading to potential deviations between actual and estimated temperatures.
Innovation Solution
A semiconductor device configuration that includes power modules with temperature detection diodes and drive circuits using hysteresis comparators to output warning and protection signals based on forward voltage thresholds, allowing for accurate temperature detection and efficient aggregation of temperature information across multiple power modules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage amplification method is used to detect temperature, then temperature detection capability is provided, but measurement precision deteriorates due to variations in output voltages and deviations between actual and estimated temperatures
Solution Approach 1:
The patent changes the detection parameter from voltage amplification to direct forward voltage comparison. By comparing the forward voltage of the temperature detection diode directly with reference voltages corresponding to threshold temperatures, the system eliminates amplification errors and achieves more accurate temperature detection without deviation between actual and estimated temperatures.
Solution Approach 2:
The patent introduces reference voltages as intermediaries to represent threshold temperatures. Instead of amplifying and interpreting varying diode voltages, the system uses stable reference voltages that directly correspond to specific temperature thresholds, eliminating the need for complex amplification and calibration while improving measurement precision and reliability.
2Loss of information
If individual temperature detection is implemented for each power module, then temperature monitoring capability is provided, but device complexity increases due to multiple detection circuits
Solution Approach 1:
The patent merges the temperature detection function into the existing drive circuit of each power module. By integrating the temperature detection diode and its comparison logic within the drive circuit, the system collects temperature information from multiple modules without adding separate detection circuits, thereby reducing overall device complexity while maintaining comprehensive monitoring capability.
Solution Approach 2:
The drive circuit is designed to perform multiple functions: power switching control and temperature detection. The same drive circuit that controls the power semiconductor switching element also monitors the temperature detection diode's forward voltage, eliminating the need for dedicated temperature detection circuits and reducing device complexity while improving information collection efficiency.
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 precise temperature detection and efficient collection of temperature data, preventing overheating by stabilizing operation and reducing false alarms through the use of adjustable reference voltage values and hysteresis comparators.
Implementation Method 1
a temperature detection diode... the value of the forward voltage of the temperature detection diode becomes equal to or smaller than a first reference voltage value
Implementation Method 2
drive circuits using hysteresis comparators to output warning and protection signals based on forward voltage thresholds
Data Source
AI summary
A semiconductor device including a plurality of power modules each of which includes a power semiconductor switching element that has a temperature detection diode, and a drive circuit that has an output circuit for switching on and off the power semiconductor switching element, and that outputs a warning signal for calling attention if the value of the forward voltage of the temperature detection diode becomes equal to or smaller than a first reference voltage value, and that outputs a protection operation signal for stopping the on/off operation of the power semiconductor switching element if the value of the forward voltage becomes equal to or smaller than a second reference voltage value smaller than the first reference voltage value. The semiconductor device outputs the logical sum of the warning signals of the individual power modules as an external warning signal.