HEMT Gate-Voltage Fault Detection Without Current Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current overcurrent fault detection methods for High Electron Mobility Transistors (HEMTs) require high-bandwidth current sensing solutions, which increase the cost of protection circuits and are not suitable for compact system solutions with short fault time constraints.
Innovation Solution
An overcurrent fault detector using a band-pass filter and control circuit that receives gate-to-source voltage signals from HEMTs, filters them to generate a band-limited version, and measures the signals to determine if they exceed a threshold, generating a fault signal to disable the gate driver and terminate the fault condition without the need for high-bandwidth current sensing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-bandwidth current sensing solutions are used for overcurrent fault detection in HEMTs, then measurement precision and response speed are improved, but device complexity and cost increase
Solution Approach 1:
The HEMT device itself serves as the sensing element by monitoring its own gate-to-source voltage signals. The intrinsic electrical characteristics of the HEMT channel provide overcurrent information without requiring external current sensors, thereby eliminating complex protection circuits while maintaining detection precision.
Solution Approach 2:
The patent extracts the fault detection function from separate current sensing circuits and integrates it into the HEMT's inherent electrical characteristics. By utilizing the gate-to-source voltage signals already present in the HEMT operation, the system removes the need for additional high-bandwidth current sensing components.
2Speed
If high-bandwidth current sensing solutions are used for overcurrent fault detection in HEMTs, then response speed is improved, but cost increases
Solution Approach 1:
The HEMT device itself serves as the sensing element by monitoring its own gate-to-source voltage signals. The intrinsic electrical characteristics of the HEMT channel provide overcurrent information without requiring external current sensors, thereby eliminating complex protection circuits while maintaining detection precision.
Solution Approach 2:
The patent replaces expensive high-bandwidth current sensing components with simpler, lower-cost signal filtering and processing circuits. The band-pass filter and threshold detection circuitry are significantly less costly than high-bandwidth current sensors while achieving comparable fault detection performance.
3Productivity
If compact system solutions with short fault time constraints are implemented, then productivity and safety are improved, but the overcurrent capability of HEMT devices is limited
Solution Approach 1:
The band-pass filter is pre-configured to pass only the frequency range containing overcurrent fault signal components. This preliminary signal conditioning ensures that when overcurrent occurs, the fault signal is already filtered and ready for immediate threshold comparison, enabling ultra-fast fault detection and termination while protecting HEMT reliability.
Solution Approach 2:
The system continuously monitors the gate-to-source voltage signals and provides immediate feedback when overcurrent conditions are detected. The control circuit compares the filtered signal against a threshold and rapidly terminates the fault condition, creating a closed-loop protection mechanism that ensures HEMT safe operation during short fault time constraints.
Data Source
AI summary
An overcurrent fault detector using a High Electron Mobility Transistor (HEMT) operated by a gate driver is disclosed. The overcurrent fault detector includes a band-pass filter and a control circuit. The band-pass filter is configured to receive gate-to-source voltage (VGS) signals of the HEMT and filter the VGS signals to generate a band-limited version of the VGS signals. The control circuit is configured to measure a value of the band-limited version of the VGS signals, determine if the value is greater than a threshold value, and generate a fault signal that disables the gate driver and terminates an overcurrent fault condition in response to determining that the value is greater than the threshold value.