Super-Junction MOSFET Buck Converter for Higher Output Power
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Solution Overview
Problem
Buck converters face limitations in achieving high output due to increased power loss and heating issues, particularly with MOSFETs, which restrict their output to approximately 10 W, making it challenging to meet higher power demands while maintaining cost-effectiveness.
Innovation Solution
The implementation of a buck converter configuration using a super-junction MOSFET, optimized switching frequency between 20 kHz to 30 kHz, and increased inductance of the coil, along with specific resistor and diode configurations, reduces power loss and enhances switching speed, thereby increasing output to approximately 20 W while maintaining cost advantages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a conventional MOSFET is used in a buck converter to achieve high output, then the output power can be increased, but the power loss and heat generation in the MOSFET increase significantly
Solution Approach 1:
The patent applies parameter changes by transitioning from a conventional MOSFET to a super-junction MOSFET, which fundamentally alters the electrical parameters of the switching element. The super-junction MOSFET exhibits lower on-resistance and faster switching characteristics, enabling the buck converter to achieve higher output power (20W or more) while maintaining acceptable power loss levels. This parameter transformation resolves the contradiction between output power and power loss.
2Power
If the output power of a buck converter is increased, then the power supply capability is improved, but the heat generation increases and limits further output expansion
Solution Approach 1:
The patent utilizes parameter changes in the MOSFET characteristics through super-junction technology. The super-junction MOSFET maintains lower on-resistance at higher current levels and exhibits improved thermal characteristics, allowing the system to deliver higher output power without proportionally increasing heat generation. This enables the buck converter to exceed the conventional 10W output limit while controlling temperature rise.
3Power
If a flyback converter is used to achieve high output, then the power supply capability is improved, but the cost increases due to expensive transformers and more parts
Solution Approach 1:
The patent applies parameter changes to the MOSFET component to enable a buck converter to achieve high output power that was previously only attainable with flyback converters. By improving the switching element's performance parameters, the simpler buck converter topology can deliver 20W or more output while maintaining its cost advantages through fewer components and simpler magnetic elements, thus resolving the contradiction between output power and manufacturing cost.
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 configuration achieves a high output with reduced power loss and heat generation, allowing the buck converter to effectively handle higher power requirements while remaining cost-competitive with flyback converters.
Implementation Method 1
the MOSFET is a super-junction MOSFET
Data Source
AI summary
The present disclosure provides a buck converter for achieving a high output and reducing cost. The buck converter includes: a MOSFET, including a first side connected to an application end of an input voltage; a rectifying element, connected to a second side of the MOSFET by a first connection node; a coil, having a first terminal connected to the first connection node; and an output capacitor, connected to a second terminal of the coil. The MOSFET is a super-junction MOSFET.