Poly-Silicon and SiC Resistor Temperature Detection Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power transistors operating in high-temperature environments are prone to damage due to insufficiently fast temperature detection circuits, which can lead to incorrect operation or premature shutdown if overly sensitive detection is employed.
Innovation Solution
A temperature detection device utilizing a poly-silicon resistor and a silicon carbon diffusion resistor in series to generate a monitoring voltage, compared against multiple reference voltages to quickly determine the temperature level, thereby protecting the power transistor from damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the temperature detection circuit is designed to be excessively sensitive, then the response speed to temperature changes is improved, but incorrect operation and erroneous shutdown of the power transistor occur
Solution Approach 1:
The temperature detection range is segmented into multiple intervals, each with its own reference voltage. The operation circuit compares the monitoring voltage against multiple reference voltages to determine which interval the current temperature falls into, enabling both fast response and accurate temperature level detection without excessive sensitivity that would cause erroneous shutdowns.
Solution Approach 2:
The patent uses resistors with different temperature coefficients (poly-silicon resistor with positive temperature coefficient and silicon carbon diffusion resistor with negative temperature coefficient) to create a monitoring voltage that changes non-linearly with temperature. This parameter change approach allows the detection circuit to cover a wide temperature range with multiple intervals, achieving fast response while maintaining reliability through proper threshold setting.
2Reliability
If the temperature detection circuit responds quickly to over-temperature, then protection of the power transistor is improved, but false detection and incorrect operation occur
Solution Approach 1:
Multiple reference voltages are pre-established corresponding to different temperature intervals before detection occurs. The operation circuit quickly compares the monitoring voltage against these pre-set thresholds to determine the temperature level, enabling fast protection response without requiring complex real-time calculations that would reduce accuracy.
Solution Approach 2:
The patent introduces an operation circuit as an intermediary that processes the comparison between monitoring voltage and multiple reference voltages. This intermediary component accurately determines which temperature interval the current temperature falls into, providing both fast response and precise temperature level detection, thereby protecting the power transistor without false detection.
3Device complexity
If a single resistor is used for voltage division, then the circuit complexity is reduced, but the temperature detection range and precision are limited
Solution Approach 1:
The patent uses a composite resistor structure combining poly-silicon resistor and silicon carbon diffusion resistor with opposite temperature coefficients. This composite approach creates a monitoring voltage with enhanced temperature sensitivity and extended detection range, achieving high measurement precision while maintaining relatively simple circuit implementation through voltage division.
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 enables rapid and accurate temperature detection, preventing damage to power transistors by using resistors with varying sensitivity to temperature changes, allowing for precise voltage division and comparison to determine the current temperature, thus ensuring correct operation.
Implementation Method 1
The first resistor and the second resistor divide a detection voltage on the detection end so as to generate a monitoring voltage
Implementation Method 2
The first resistor is a poly-silicon resistor, and the second resistor is a silicon carbon diffusion resistor
Data Source
AI summary
An electronic device and a temperature detection device thereof are provided. The temperature detection device includes a first resistor, a second resistor, and an operation circuit. The first resistor and the second resistor are coupled in series between a detection end and a first voltage. The first resistor and the second resistor divide a detection voltage on the detection end to generate a monitoring voltage. The operation circuit compares the monitoring voltage with a plurality of reference voltages to generate a plurality of comparison results. The operation circuit performs an operation on the comparison results to generate detection temperature information. The first resistor is a poly-silicon resistor and the second resistor is a silicon carbon (SiC) diffusion resistor.