- Interwinding capacitance down to <1 pF
- Tiny surface mount EP7 package
- Dielectric insulation up to 4 kV AC
- Basic insulation for 568 Vrms / 800 Vpk
- Safety: IEC62368-1 / IEC61558-2-16
- AEC-Q200 qualification
- Operating temperature: -40 °C up to +130 °C
- Common control voltages for SiC MOSFET’s
- High Common-mode Transient Immunity (CMTI)
- Flyback, LLC, Half-Bridge topologies
- Up to 6 W output power
- Wide range input voltages 6 V to 36 V
- Different unipolar and bipolar voltages
- High efficiency and very compact solution
- Reference designs with Analog Devices, Texas Instruments, and onsemi
- Industrial drives
- AC motor inverters
- HEV/EV charging station
- Battery chargers
- Solar inverters
- Data centers
- Uninterruptible power supplies
- Active power factor correction
- SiC-MOSFET based power converter
Impact of Interwinding Capacitance
Importance of minimizing displacement current / common-mode current
SiC-MOSFETs can switch extremely fast, causing very high rates of rise and fall of voltage (dv/dt) across the device terminals and in turn, across the isolation barrier parasitic capacitances, which are a contribution of the transformer in the auxiliary supply (Ciso-xfmr) and the gate driver IC controller or digital isolator used (Ciso-drv).
As a result, common-mode displacement currents are generated which, if high enough, may cause loss of control of the SiC-MOSFET device as well as EMI issues, since high dv/dt also appears across PCB nodes and Earth/Chassis. The lower the parasitic capacitance, the lower the displacement currents generated, helping to prevent such issues.
Compared to regular transformers
The WE-AGDT transformers have been engineered with extremely-low interwinding capacitance in order to help the application withstand higher switching speeds (dv/dt), and with it to achieve higher efficiency as well as a smaller solution size and lower system cost.
Compared to regular, same-sized transformers, the WE-AGDT feature less than half of the parasitic capacitance, as required by state-of-the-art SiC-MOSFET and IGBT applications.
SiC Gate Driver System
One of the main applications of high-voltage SiC-MOSFETs and IGBTs is in high-power AC inverters and AC-Motor drives. Such power stages are built by ‘paralleling’ several half-bridge configurations of SiC devices in order to generate the different phase currents and voltages for the load.
Each of the SiC-MOSFET devices typically has its own isolated gate driver system formed by the gate driver IC and the auxiliary supply (e.g. Würth Elektronik RD001 reference design with WE-AGDT).
A simplified schematic of an example application of a 3-phase inverter formed by three half-bridge stages paralleled and six SiC-MOSFET devices in total is shown in the image, in addition to a detail connection of the isolated auxiliary supply, isolated gate driver IC and the corresponding SiC-MOSFET device.
WE meet @ Digital Days 2020: SiC Gate Driver Systems with WE-AGDT series