Wireless Charging Witricity Electric Vehicle Charger SiC EV Wireless Charging SiC High Efficiency Better Thermal High Frequency Switching Advanced Topology for High Efficiency Power Transfer Silicon Carbide MOSFET Technology High Current Silicon Carbide and Ultrafast Rectifiers Silicon Carbide Driving Methods Advanced Topology for High Efficiency Power Transfer Switch 11kW EV Charging System Part Numbers 2x D1, D2 STPSC20H065C 650 V power Schottky silicon carbide diode 2x Q1, Q2 SCTW90N65G2V N-channel 650 V, 0.029 Ohm typ., 90 A SiC MOSFET Q3, Q4, Q5, Q6 SCTW90N65G2V N-channel 650 V, 0.029 Ohm typ., 90 A SiC MOSFET D3,D4,D5,D6 U1, U2, U3, U4, U5, U6 MCU STTH30L06WY 30A 600V Fast Rectifiers TD350 1.5A IGBT, MOSFET advanced gate driver 26V -10V STM32F405 Cortex M4 Automotive Solution Standards-Compliant Highlights • Delivers 3.3kW, 6.6kW, 11kW or more power wirelessly to compatible electric vehicle • WiTricity is working on wireless charging standards with SAE and other organizations • Spatial freedom for “park-and-charge” user WiTricity wireless EV charging systems are “park-and-charge” experience with high efficiency (92%-94%) • Foreign Object Detection (FOD) Automotive Solution Specifications PTU • 3.3kW, 6.6kW and 11kW+ continuously variable ground assembly units (GA) • Efficiency: Up to 98% coil-to-coil • Operating Frequency: 85 kHz • Operating Height: 9 - 28cm vehicle ground clearance • Communications: WiFi • Foreign Object Detection: Yes • Standards: SAE, ISO, IEC pending • Regulatory: meets FCC, CISPR, ICNIRP guidelines for Emissions and human safety Silicon Carbide MOSFET Technology Extremely low Power Loss and Low Ron especially at very high Tj Higher operating frequency for Smaller and lighter systems Easy to Drive Fully compatible with standard Gate Drivers Thermal Performance High operating temperature ( Tjmax = 200°C) Reduced cooling requirements & heat-sink Increased life time Silicon Carbide MOSFET Technology SCTW90N65G2V • SCT3W90N65G2V - SiC Power MOSFET, 90A, 650V, 25mΩ • Key parameters: • • • • • • VBR > 650V Ids = 90A Ron(typ.) @ 150°C = 29mΩ Qg(typ.) < 190nC Gate driving voltage = 20V HiP247™ package → Tjmax = 200°C • Key features: • • • • • • Very tight variation of on-resistance vs. temperature Slight variation of switching losses vs. temperature Very high operating temperature capability (200°C) Very fast and robust intrinsic body diode Low capacitance Easy to drive • Schedule: • Full Production June 2016 Silicon Carbide Diodes Low switching losses Full Series Best efficiency 600-1200V & AG High Peak Current – Low Vf Insulated Packages Better Thermal - Lower Cost Isolated metal-frame Ceramic Insulator (2500Vrms) Wire(s) die New 1200V Silicon Carbide Diodes Best in class Forward voltage characteristics IFSM (10ms) 120 100 (A) 60 Vendor 3 300mV better VF 80 Excellent Robustness with high IFSM level Vendor 2 STPSCxxH12 40 Vendor 1 20 VF (Io / 25 C) 0 1.4 1.5 1.6 1.7 1.8 (V) 1.9 2 2.1 Ultrafast Rectifiers Pt doped for low leakage (1/100) STTHxxx 200-1200V, 1-200A, 175°C Silicon Carbide Driving Methods • Driving a SiC MOSFET is almost easy as driving a silicon MOSFET: • Just need Vgs = 20V to get the right Ron • Adequate current capability to ensure high speed (2-3 A would be the best) • Recommended -4Vgs drive on turn off to minimize effects of high dv/dt on gate • Very simple and very mature standard gate drivers can be used • ST TD350 + push-pull stage (to increase current capability) in production • The new ST isolated GAPdriver: STGAP1S • An Application Note focused on “How to Drive a SiC MOSFET” has been published on st.com. SiC MOSFET driving circuit Driving SiC MOSFET with TD350E The ST TD350E is an advanced gate driver for IGBTs and power MOSFETs. To drive a SiC MOSFET, simply need to add an external push-pull network to increase the current capability. The optimal value of the resistors of the push/pull stage (RG-on & RG-off) are between 2.2Ω/6.8Ω according to dv/dt requirements. 20V TD350E IN VREF Rgon DESAT VH STD1802T4 FAULT OUTH NC1 OUTL COEFF NC2 LVOFF VL CLAMP Rb SCT30N120 SiC MOSFET Cb STN951 GND Rgoff 0V/-4V