Synchronous Rectification Current Detection for Power Supply Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power supply apparatuses face challenges in achieving high efficiency due to the limitations of synchronous rectification circuits, particularly with low on-resistance field effect transistors and the inability to apply to forward-type power supply systems, necessitating a solution that is not influenced by the on-resistance of switching elements and can accommodate various power supply systems.
Innovation Solution
A power supply apparatus with a transformer, switching elements, a rectification unit, a secondary-side smoothing element, a current detection unit, and a driving unit, which includes a current detection circuit to manage the rectification process based on detected current, allowing for efficient operation across different power supply systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a comparator is used to determine the voltage between both ends of the synchronous rectification switching element, then the voltage control is achieved, but it becomes difficult to perform synchronous rectification operation with low on-resistance FETs
Solution Approach 1:
The patent changes the detection parameter from voltage (comparator-based) to current (current detection unit). By detecting the current flowing into the secondary-side smoothing element and using this current information to control the rectification unit, the system achieves synchronous rectification operation with low on-resistance FETs without being limited by voltage detection methods.
2Device complexity
If the ET product detection system is used, then the current detection is achieved without direct current measurement, but it cannot be applied to forward-type power supply systems
Solution Approach 1:
The patent creates a universal current detection method that can be applied to various power supply systems including forward-type systems. By directly detecting the current flowing into the secondary-side smoothing element and using this detection result to control the rectification unit, the system achieves compatibility across different power supply architectures without being restricted to specific topologies.
3Loss of energy
If conventional synchronous rectification circuits are used, then the rectification function is achieved, but the power supply efficiency cannot be further improved due to influence from switching element on-resistance
Solution Approach 1:
The patent implements a feedback control mechanism where the current detection unit continuously monitors the current flowing into the secondary-side smoothing element, and the driving unit uses this detection result to adjust the operation of the rectification unit. This feedback loop enables optimal control of synchronous rectification, minimizing energy losses while maintaining ease of operation through automated current-based control.
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 proposed solution improves the efficiency of the power supply apparatus by effectively managing the rectification process, reducing losses, and enabling operation in various power supply systems, including those with low on-resistance switching elements.
Implementation Method 1
a transformer including a primary winding and a secondary winding
Implementation Method 2
a rectification unit configured to be driven to rectify a current flowing into the secondary winding
Implementation Method 3
a secondary-side smoothing element configured to smooth a voltage rectified by the rectification unit
Data Source
AI summary
The power supply apparatus of a synchronous rectification systems includes a current detection unit configured to detect a current for charging a secondary-side smoothing element, and a driving unit configured to drive a rectification unit based on a detection result by the current detection unit.