Transistors|Evaluation
Basic Configuration of an LLC Converter
2024.01.22
Points of this article
・In an LLC converter, a series circuit of two inductors (L) and a capacitor (C) is formed.
・Because of the ZCS operation of the diodes used on the secondary side, recovery losses do not occur.
・As a result, when diodes with a low forward voltage VF are selected, losses can be reduced.
Here the first topic, the basic configuration of an LLC converter, is explained.
- ■ Basic Configuration of an LLC Converter
- ■ Features of LLC Converter Operation
- ■ Basic Operation of LLC Converters
- ■ Importance of MOSFET Recovery Characteristics for Off-Resonance of LLC Converters
Basic Configuration of an LLC Converter
Fig. 1 shows the basic circuit diagram of an LLC converter. A series circuit is formed by the inductors Lr and Lm and the capacitor Cr, which are the origin of the name “LLC converter”. Lr is the resonant inductance, Lm is the transformer’s magnetizing inductance, and Cr is the resonant capacitor.
Inductive components of the transformer mainly include the magnetizing inductance Lm and a leakage inductance Ll, but in general, in many LLC converters the leakage inductance Ll is put to use as a resonant inductor Lr. With respect to the diodes used on the secondary side, because of the ZCS operation, recovery losses do not occur. By selecting diodes with a low forward voltage VF, losses can be reduced.

Transistors
Basic
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Basics of Transistors
- Transistor Fundamentals: Structure, Types, and Operating Principles
- Bipolar Junction Transistor (BJT) Basics: Operation and Applications (NPN & PNP)
- NPN Transistor: Low-Side Switch Fundamentals
- PNP Transistor: High-Side Switch Fundamentals
- What is a Digital Transistor?
- Digital Transistor Selection
- ON Resistance
- Total Gate Charge
- How to select<Selecting Transistors to Ensure Safe Operation>
- Junction Temperature <Calculating Transistor Chip Temperature>
- What is a Load Switch?
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Basics of MOSFETs
- What are MOSFETs? – MOSFET Parasitic Capacitance and Its Temperature Characteristic
- What are MOSFETs? – MOSFET Switching Characteristics and Temperature Characteristics
- What are MOSFETs? – MOSFET Threshold Values, ID-VGS Characteristics, and Temperature Characteristics
- What are MOSFETs? – Super-junction MOSFET
- What are MOSFETs? – Types and Features of High Voltage Super-Junction MOSFET
- What are MOSFETs? – Fast trr SJ-MOSFET:PrestoMOS™
- MOSFET Thermal Resistance and Power Dissipation: Packages Capable of Back-Surface Heat Dissipation
- Introduction
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Confirming the Suitability of a Transistor in Actual Operation – Introduction
- Confirmation of the Chip Temperature
- Confirmation of Suitability in Actual Operation and Preparations
- Confirmation that Absolute Maximum Ratings are Satisfied
- Confirmation that Operation is within the SOA (Safe Operating Area)
- Confirmation that Operation is within the SOA Derated at the Actual Operating Temperature
- Confirmation that Average Power Consumption is within the Rated Power
- Summary
- Summary
Evaluation
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The Importance of the Recovery Characteristics of Primary-side Switching Elements in LLC Converters -Introduction-
- Basic Configuration of an LLC Converter
- Features of LLC Converter Operation
- Basic Operation of LLC Converters
- Importance of MOSFET Recovery Characteristics for Off-Resonance of LLC Converters
- The Importance of the Recovery Characteristics of Primary-side Switching Elements in LLC Converters ーSummaryー
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The Importance of the Reverse Recovery Characteristics of Switching Elements in Inverter Circuits -Introduction-
- Types of Inverter Circuits and Energization Methods
- Basic Operation of 3-Phase Modulation Inverter Circuits
- Comparison of Losses in a PrestoMOS™ MOSFET and a Standard SJ MOSFET Using Double-Pulse Tests (Actual Measurement Results)
- Comparison of Efficiency of a PrestoMOS™ MOSFET and a Standard SJ MOSFET in a 3-Phase Modulation Inverter Circuit (Simulations)
- The Importance of the Reverse Recovery Characteristics of Switching Elements in Inverter Circuits -Summary-
- Mechanisms of MOSFET Destruction
- About Double-Pulse Tests
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Improving the Power Conversion Efficiency of Phase Shift Full Bridge Circuits – Introduction
- Basic Configuration of a PSFB Circuit
- Basic Operation of PSFB Circuits
- Guidelines Relating to Operation of Switching Elements Under Light Loading
- Guidelines Relating to Operation of Switching Elements Under Heavy Loading
- Evaluation of Efficiency
- Improving the Power Conversion Efficiency of Phase Shift Full Bridge Circuit – Summary –