Switching Element Overcurrent Detection Using Temperature-Variable Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The function of protecting a switching element in a semiconductor device deteriorates when the temperatures of the switching element and the control circuit controlling it are different from each other.
Innovation Solution
A semiconductor device with a temperature detection section and a current detection section, where a control circuit generates a temperature variable signal based on the switching element's temperature, allowing accurate overcurrent detection by comparing it with a current detection signal, independent of the control circuit's temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the control circuit uses a fixed overcurrent reference voltage for protection, then the circuit structure is simple, but the protection accuracy deteriorates when temperature differences exist between the switching element and control circuit
Solution Approach 1:
The patent changes the reference voltage parameter dynamically based on temperature detection. The reference voltage generation circuit adjusts the overcurrent reference voltage according to the detected temperature of the switching element, ensuring accurate overcurrent protection across different temperature conditions while maintaining a relatively simple circuit structure.
2Measurement precision
If temperature compensation is implemented using detection diodes in both switching element and control circuit, then the protection accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent extracts the temperature detection function from the control circuit and places it directly in the switching element through a temperature detection diode. This allows the control circuit to receive accurate temperature information from the switching element itself, improving protection accuracy without requiring complex temperature compensation circuits in the control circuit.
3Device complexity
If the control circuit temperature is used for overcurrent detection, then the circuit structure is simple, but the protection function deteriorates when temperature differs from switching element
Solution Approach 1:
The patent introduces a temperature detection diode as an intermediary element that directly contacts the switching element. This diode acts as a mediator to transfer temperature information from the switching element to the control circuit, ensuring that the control circuit bases its protection decisions on the actual switching element temperature rather than its own circuit temperature.
Data Source
AI summary
There is provided a semiconductor device capable of preventing a deterioration of a function of protecting a switching element to be protected, even when the temperatures of the switching element and a control circuit controlling the switching element are different from each other. A semiconductor device includes: a semiconductor element having a switching element, a temperature detection section, and a current detection section; and a control circuit configured to control the semiconductor element, in which the control circuit has a signal generation section configured to generate a temperature variable signal varying according to a detection temperature detected by the temperature detection section using a temperature detection signal having information on the detection temperature, and an overcurrent detection section configured to detect that a current flowing into the switching element is an overcurrent using a current detection signal having information on a detection current detected by the current detection section and the temperature variable signal output from the signal generation section.