SiC Power Device｜Application
SiC MOSFETs： Snubber Circuit DesignsRC Snubber Circuit Design
2024.10.09
Points of this article
・When designing an RC snubber circuit, CSNB and RSNB are determined taking the power dissipation PSNB into consideration, and the resonance angular frequency ωSNB must be set well above the surge resonance angular frequency ωSURGE.
In succession to the previous article addressing C snubber circuits, here the design of RC snubber circuits is explained.
- Surges occurring between drain and source
- Types and selection of snubber circuits
- C snubber circuit design
- RC snubber circuit design
- Discharge RCD snubber circuit design
- Non-discharge RCD snubber circuit design
- Difference in surge occurrence depending on package
SiC MOSFET: RC Snubber Circuit Design
Fig. 7 shows the current paths in an RC snubber circuit during operation. As in the case of “C Snubber Circuit Design”, CSNB is determined using equation (2). Equation (3) below provides a rough value for RSNB.
fSW：Switching frequency
VSNB：Discharge snubber voltage (0.9 ×VDS_SURGE)
After RSNB has been determined, the power PSNB dissipated in RSNB is calculated using equation (4), and a resistor for which such a loss is tolerated is selected.
In the case of an RC snubber circuit, the second term in equation (4) is added, and the higher the value of fSW or VHVDC, the greater is the amount of power dissipated in RSNB. Hence when PSNB is large and resistor selection is difficult, it will be necessary to reduce the capacitance value of CSNB and recalculate.
Further, in order to ensure that the RC snubber circuit adequately absorbs surges, the resonance angular frequency ωSNB of RSNB and CSNB must be considerably higher than the surge resonance angular frequency ωSURGE. Therefore, the resonance angular frequency ωSNB of the RC snubber circuit, calculated using equation (5), must be checked.
【Download Documents】 Basics of SiC Power Devices
This handbook explains the physical properties and advantages of SiC, the differences in characteristics and usage of SiC Schottky barrier diodes and SiC MOSFETs with a comparison to Si devices, and includes a description of full SiC modules with various advantages.
SiC Power Device
Basic
- What are SiC Schottky barrier diodes? ? Introduction
- What are SiC-MOSFETs? – SiC-MOSFET Features
- What are Full-SiC Power Modules?
- Summary
- Introduction
- What is silicon carbide?
Application
-
Introduction
- SiC MOSFET Bridge Configuration
- SiC MOSFET Gate Driving Circuit and Turn-On/Turn-Off Operation
- Currents and Voltages Occurring Due to Switching in Bridge Circuits
- Behavior of the Gate-Source Voltage During Low-side Switch Turn-on
- Behavior of the Gate-Source Voltage During Low-side Switch Turn-off
- Summary
- SiC MOSFETs: Method for Determining Losses from Switching Waveforms
-
SiC MOSFETs： Snubber Circuit Designs ーIntroductionー
- Non-Discharge RCD Snubber Circuit Design
- Surges Occurring between Drain and Source
- Types and Selection of Snubber Circuits
- C Snubber Circuit Design
- RC Snubber Circuit Design
- Discharge RCD Snubber Circuit Design
- Non-Discharge RCD Snubber Circuit Design
- Differences in Surge Occurrence Depending on Package
- SiC MOSFETs： Snubber Circuit Designs ーSummaryー
- Points to Note When Measuring SiC MOSFET Gate-Source Voltages: General Measurement Methods
-
Conventional MOSFET Driving Method
- Packages Provided with Driver Source Terminals
- Differences Made by and Benefits of a Driver Source Pin
- Benefits of a Driver Source Terminal: Comparisons Using Double Pulse Tests
- Behavior of Gate-Source Voltages when in a Bridge Configuration: Behavior at Turn-on
- Behavior of Gate-Source Voltages when in a Bridge Configuration: Behavior at Turn-off
- Points to be Noted Relating to Board Wiring Layout Key Points of This Article
- Verification of Loss Reduction Using Latest-Generation SiC MOSFETs
- About Surges in Gate-Source Voltages
Product Information
- SiC Schottky Barrier Diodes
- SiC MOSFET
- SiC Power Modules
- SiC Schottky barrier diode Bare Die
- SiC MOSFET Bare Die
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