Gate Resistor Negative Temperature Coefficient for Transistor Voltage Margin
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices, particularly field-effect controlled switching devices like JFETs, MOSFETs, and IGBTs, experience switching losses and overvoltages during turn-off operations, which can lead to electric breakdown, and existing designs struggle to maintain a sufficient voltage margin between breakdown voltage and overvoltages across varying temperatures without increasing switching losses.
Innovation Solution
Incorporating a gate resistor with a negative temperature coefficient between the gate terminal and gate electrode of a discrete semiconductor transistor, which adjusts the temperature characteristic of overvoltages and reduces resistance with increasing temperature, thereby improving the voltage margin and reducing switching losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a gate resistor with positive temperature coefficient is used, then switching losses are reduced at high temperatures, but voltage margin deteriorates at low temperatures
Solution Approach 1:
The patent changes the temperature coefficient parameter of the gate resistor from positive to negative. This parameter change allows the resistance to decrease with increasing temperature, which reduces switching losses at high temperatures while maintaining sufficient voltage margin at low temperatures, thereby resolving the contradiction between switching losses and voltage margin across the temperature range.
Solution Approach 2:
The patent makes the gate resistor dynamic by selecting a resistor whose resistance value changes with temperature (negative temperature coefficient). This dynamic behavior allows the gate resistor to automatically adapt its resistance: higher resistance at low temperatures to maintain voltage margin, and lower resistance at high temperatures to reduce switching losses, thus resolving the contradiction without external control.
2Reliability
If gate resistance is increased to improve voltage margin at low temperatures, then switching losses increase
Solution Approach 1:
The patent changes the temperature dependency parameter of the gate resistor to negative temperature coefficient. This allows the resistance to be high at low temperatures (improving voltage margin) and low at high temperatures (reducing switching losses), thereby resolving the contradiction between voltage margin and switching losses through temperature-dependent parameter variation.
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 effectively enhances the voltage margin between breakdown voltage and overvoltages across the temperature range, ensuring safe operation and reducing switching losses, particularly at lower temperatures where the voltage margin is critical.
Implementation Method 1
A resistance R of the gate resistor at a temperature of −40° C. is greater than at the temperature of 150° C.
Data Source
AI summary
A discrete semiconductor transistor includes a gate resistor electrically coupled between a gate electrode terminal and a gate electrode of the discrete semiconductor transistor. A resistance R of the gate resistor at a temperature of −40° C. is greater than at the temperature of 150° C.