Electroluminescence-Based ZVS Control for Switch Transistors
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Solution Overview
Problem
Existing zero-voltage switching (ZVS) methods face challenges in accurately controlling switching status and calculating required reverse currents, leading to increased conduction losses and current ripples due to inaccurate detection and complex control algorithms.
Innovation Solution
A circuit adaptive zero-voltage switching control method that uses an opto-sensor to detect electroluminescence in a switch transistor, adjusting the switching frequency based on the presence or absence of electroluminescence to achieve optimal zero-voltage switching without requiring electrical parameter measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If zero-voltage switching is implemented by overdesigning reverse load current to completely discharge output capacitor, then zero-voltage switching is achieved, but current ripple and conduction losses increase significantly
Solution Approach 1:
The patent replaces electrical signal-based detection (current sensors, saturable inductors, voltage measurements) with optical detection using electroluminescence. The opto-sensor detects photons emitted by the body diode during forward conduction, providing a non-contact, noise-immune method to determine zero-voltage switching timing without the losses and interference inherent in electrical measurement systems
Solution Approach 2:
The patent introduces electroluminescence photons as an intermediary signal to indicate switching status. The body diode's forward conduction generates detectable photons that serve as a clean, unambiguous marker for the optimal switching moment, eliminating the need for complex electrical parameter measurements and calculations
2Difficulty of detecting and measuring
If electrical signals are used for zero-current detection and delay calculation to determine zero-voltage moment, then switching status can be detected, but additional losses and response delays are introduced
Solution Approach 1:
The patent replaces electrical signal-based detection (current sensors, saturable inductors, voltage measurements) with optical detection using electroluminescence. The opto-sensor detects photons emitted by the body diode during forward conduction, providing a non-contact, noise-immune method to determine zero-voltage switching timing without the losses and interference inherent in electrical measurement systems
3Measurement precision
If measurements are made using current sensors, saturable inductors, and drain-source voltages, then zero-current point can be measured, but electromagnetic noise interference occurs
Solution Approach 1:
The patent replaces electrical signal-based detection (current sensors, saturable inductors, voltage measurements) with optical detection using electroluminescence. The opto-sensor detects photons emitted by the body diode during forward conduction, providing a non-contact, noise-immune method to determine zero-voltage switching timing without the losses and interference inherent in electrical measurement systems
4Measurement precision
If control algorithm is developed to determine optimal zero-voltage switching time based on non-linear characteristics and dynamic operating states, then accurate switching timing can be achieved, but computational complexity increases
Solution Approach 1:
The patent introduces electroluminescence photons as an intermediary signal to indicate switching status. The body diode's forward conduction generates detectable photons that serve as a clean, unambiguous marker for the optimal switching moment, eliminating the need for complex electrical parameter measurements and calculations
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 accurate and stable zero-voltage switching, reducing conduction losses and current ripples, and allows the circuit to adapt to changing load conditions without complex calculations or additional losses.
Implementation Method 1
detect whether there is electroluminescence in a switch transistor in a circuit; if the disposed opto-sensor does not detect, within a current switching cycle of the circuit, an electroluminescent photon in a body diode (parasitic diode) or an anti-parallel freewheeling diode of the switch transistor
Data Source
AI summary
A circuit adaptive zero-voltage switching control method based on switch transistor electroluminescence, an electroluminescence detection circuit, and an assembly structure thereof. Switching status is detected based on an electroluminescence effect, and gate switching of a device is autonomously controlled, implementing adaptive zero-voltage switching operation under both steady-state and transient-state loading conditions. Two signal receiving and amplifying assemblies are used in a differential mode in the detection circuit, to increase a signal-to-noise ratio of the electroluminescence detection circuit with an ultra-high amplification gain. A first silicon photomultiplier of a first signal receiving and amplifying assembly is close to a to-be-detected switch transistor die in a power module of an embedded printed circuit board and can sense electroluminescence in the switch transistor die. A second silicon photomultiplier of a second signal receiving and amplifying assembly is outside an electroluminescence transmission region to eliminate potential noise caused by ambient light and electromagnetic interference.