Gate Charge Measurement for Solid State Device Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solid state devices used in applications like circuit breakers and e-Fuses face challenges in verifying their operational state over extended periods, leading to potential catastrophic failures due to undetected deterioration or critical failures.
Innovation Solution
A gate charge and leakage measurement test sequence is implemented, which includes charging a capacitor, disconnecting the gate driver from the supply voltage, and measuring the gate charge and leakage current of the solid state device during operation, using a series switch and a buffer capacitor to facilitate in-situ testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous monitoring of solid state device operational state is implemented, then reliability is improved, but device complexity increases
Solution Approach 1:
The solid state device performs self-diagnosis by monitoring its own gate charge and leakage current through integrated test circuits. The device uses internal capacitors and switches to conduct measurements without requiring external testing equipment, enabling autonomous health monitoring that improves reliability while avoiding additional external complexity
Solution Approach 2:
The gate driver circuit serves multiple functions: it drives the solid state device during normal operation and simultaneously performs diagnostic measurements during idle periods. The same capacitor and switch components used for device operation are repurposed for measurement, eliminating the need for separate dedicated testing hardware and reducing overall system complexity
2Productivity
If in-situ testing is performed during operation, then productivity is improved, but measurement precision may be compromised
Solution Approach 1:
The diagnostic measurement is performed periodically during idle periods when the solid state device is not conducting load current. The test sequence activates only during these intervals, allowing measurements to be taken without interference from load conditions while maintaining continuous operational monitoring capability
Solution Approach 2:
The measurement process extracts and isolates the gate charge and leakage current signals from the operational signals. By separating the diagnostic measurement function from the operational function and performing measurements during idle periods when load current is zero, the system achieves precise measurements without compromising productivity
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
This method enables highly efficient in-situ diagnostics of gate charge and leakage properties, allowing for early detection of potential failures and reducing the risk of catastrophic events in safety-critical applications.
Implementation Method 1
a capacitor connected to the switch and to a gate driver configured to drive a gate of a solid state device, wherein the gate driver is operated to perform a test sequence for the solid state device
Implementation Method 2
the gate driver drives the gate of the solid state device based at least upon a charge of the capacitor
Implementation Method 3
A gate charge at the gate of the solid state device is measured as an operational state of the solid state device
Data Source
AI summary
An apparatus comprises a switch and a capacitor connected to the switch and to a gate driver that drives a gate of a solid state device. The gate driver is operated to perform a test sequence for the solid state device. The test sequence includes turning on a switch and charging a capacitor to a supply voltage during an initial phase. During a first phase, the switch and the solid state device are turned off, the gate driver is disconnected from the supply voltage, and the gate driver drives the gate of the solid state device based at least upon a charge of the capacitor. During a second phase, the gate driver drives the gate of the solid state device to turn on the solid state device. A gate charge at the gate of the solid state device is measured as an operational state of the solid state device.