Adaptive Synchronous Rectifier Timing to Prevent Reverse Current
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Solution Overview
Problem
Synchronous rectifiers require accurate control to prevent current flow in the wrong direction and maximize switch conduction time, but existing systems often result in significant losses and malfunctions due to improper timing of switch activation.
Innovation Solution
A synchronous rectifier with a controller that adjusts the timing of on and off triggers based on reference time points and timing offsets, using GaN MOSFETs and a dual-edge adaptive control mechanism to optimize switch operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If fixed timing control is used for rectifier switches, then control simplicity is maintained, but conduction losses increase and efficiency decreases
Solution Approach 1:
The patent applies dynamics by transitioning from fixed timing control to adaptive timing control where the timing offsets are dynamically adjusted based on operating conditions. The controller iteratively determines optimal timing offsets for turn-on and turn-off triggers, allowing the system to adapt to varying load and voltage conditions, thereby minimizing conduction losses while maintaining manageable control complexity through algorithmic optimization.
Solution Approach 2:
The patent implements feedback mechanisms by monitoring the actual switching performance and iteratively adjusting the timing offsets. The controller uses feedback from voltage and current measurements to optimize the timing of switch activation and deactivation, ensuring maximum conduction time while preventing reverse current flow, thus reducing energy losses without excessive complexity.
2Loss of energy
If switch conduction time is extended to maximize efficiency, then energy loss decreases, but risk of current flowing in wrong direction increases
Solution Approach 1:
The patent applies preliminary action by calculating and setting appropriate timing offsets before the switching events occur. The controller determines the optimal turn-on trigger timing offset to maximize conduction time while preemptively establishing the turn-off trigger timing offset to prevent reverse current flow. This advance planning ensures both efficiency and reliability are maintained.
Solution Approach 2:
The patent uses feedback to continuously monitor switching performance and adjust timing offsets iteratively. By feedback from voltage and current measurements, the controller optimizes the conduction time while maintaining safety margins that prevent current flowing in the wrong direction, thus balancing efficiency improvement with reliability maintenance.
3Loss of energy
If timing offsets are adjusted to optimize steady-state efficiency, then conduction losses are minimized, but performance during transient conditions may deteriorate
Solution Approach 1:
The patent applies dynamics by implementing adaptive timing control that can respond to changing operating conditions. The controller iteratively adjusts timing offsets based on real-time measurements, allowing the system to optimize for steady-state efficiency while maintaining the capability to adapt during transient conditions. This dynamic adjustment ensures both efficiency and adaptability are achieved.
Solution Approach 2:
The patent implements parameter changes by iteratively adjusting the timing offset parameters based on operating conditions. The controller modifies the turn-on and turn-off timing offsets to optimize conduction losses during steady-state operation, while the iterative nature of the adjustment process allows the system to adapt to transient conditions, maintaining both efficiency and versatility.
Data Source
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AI summary
A synchronous rectifier (140) includes at least a first rectifier switch (141), arranged to switch between an on state and an off state. The synchronous rectifier also includes a controller (150) arranged to output a first control signal for the first rectifier switch (141). The first control signal has a first on trigger and a first off trigger. The controller (150) is arranged to determine the timing of at least one of the first on trigger or the first off trigger based on a reference time point and a first timing offset.