https://www.specterengineering.com/blog daily 0.75 2020-05-03 https://www.specterengineering.com/blog/2019/9/26/switch-node-ringing monthly 0.5 2020-11-09 https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1570139848281-IX7QOYRL72F1II5HAPVT/image-asset.png Blog - Switch Node Ringing Figure 1: Measured ringing on switch node of synch. buck converter https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1604943271450-95OVYRCEEE3FV69377V4/equation+1.PNG Blog - Switch Node Ringing Equation 1 https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1569969377692-WGBUHL3DUX9IBE41OVY3/image-asset.jpeg Blog - Switch Node Ringing Figure 2: Synchronous Buck Converter Schematic. Parasistics not shown https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1569973858040-RKMZYOP200NS1JQFUS0I/state+1.png Blog - Switch Node Ringing Figure 3: State 1 - Low-side switch is closed https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1569973833154-JJ3PL9FZJI7SC5HNEEB6/state2.png Blog - Switch Node Ringing Figure 4: State 2 - Low side switch opens and deadtime period begins https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1569973801109-EY5ES62MZVALBFHVDUY1/image-asset.jpeg Blog - Switch Node Ringing Figure 5: State 3 - Deadtime period ends, High-side switch closes https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1569973779376-M4RK27SEJK4V956AWDLP/state4.jpg Blog - Switch Node Ringing Figure 6: State 4 - Reverse recovery period of diode ends, Low-side switch presents cap load to circuit https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1569973045400-U7YYSZ04W5GZPUFN132N/image-asset.png Blog - Switch Node Ringing Figure 7: Equivalent circuit for overshoot analysis https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1569974053513-7BWG6BP9MLWPXL83CKHK/image-asset.jpeg Blog - Switch Node Ringing Figure 8: Normalized capacitor voltage (C_OSS) vs. ω_n * t for various values of ζ (damping ratio) https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1604943401586-WOV5OCXJ0IOASORMQ8BS/image-asset.png Blog - Switch Node Ringing Equation 2 https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1570128359309-KKZHQXZIQXTZRWA9KDHC/image-asset.png Blog - Switch Node Ringing Figure 9: LTSpice simulation schematic for evaluating how changes in DC link inductance affect ringing on the switch node. https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1570128158760-E6RFV73VHCSDDHT85DXS/image-asset.png Blog - Switch Node Ringing Figure 10: Plot showing relationship between voltage overshoot vs DC link stray inductance https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1570157384993-S2IVG1SOJBBI5A5SU1QC/busbars.jpg Blog - Switch Node Ringing Figure 11: DC laminated bus structure under study for Wolfspeed’s 250 kW traction inverter. [2] https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1570157349762-1BUVCC0W48ZMT8TH5LE4/image-asset.png Blog - Switch Node Ringing Figure 12: Wolfspeed’s 16 kg, 250 kW SiC based liquid-cooled, three - phase inverter. [2] https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1570161178013-WMTY9Z2VGE1MNXZ0XPRQ/image-asset.png Blog - Switch Node Ringing Figure 13: Gate Resistance vs. Voltage Overshoot. Same schematic that’s shown in Figure 9 was used for this analysis - 400V DC bus, synchronous buck converter, RL load, etc. https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1570206689264-3F6G47M7NV65FKQJ7RQJ/image-asset.png Blog - Switch Node Ringing Figure 14: A comparison of ringing on the drain-source voltage waveforms with and without an external schottky diode. There is almost a 90V reduction. https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1570208938544-Z3VA765UQ0TZ0WBMG8GZ/capcoupling4.PNG Blog - Switch Node Ringing Figure 15: RC snubber is added in parallel with the low-side switch to reduce ringing. https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1570138412859-ZJJK40YP06BM3H9ZVP3I/image-asset.png Blog - Switch Node Ringing Figure 16: Graph of MOSFET capacitance from CAB450M12XM3 datasheet https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1570217121285-28P5XZSLCU8J8L0BYS0F/capcoupling3.png Blog - Switch Node Ringing Figure 17: Feedback/Miller capacitor that connects from gate to drain of MOSFET. Induced currents can lead to parasitic turn-on. https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1570217731130-OAZD5E72NQAROK464SYB/SiCGateDriver+-+top.PNG Blog - Switch Node Ringing Figure 18: SiC half-bridge [4] https://www.specterengineering.com/blog/2019/9/7/dc-link-capacitor-selection-for-your-inverter monthly 0.5 2020-11-09 https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1568139027563-GHHBPT6RAKOEMYNWPW22/inverter.jpg Blog - Inverter DC Link Capacitor Selection Figure 1: Simplified Inverter Circuit Diagram [1] https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1604943707776-TH8CEH7VCSRT7XELO3T7/eqn5339.png Blog - Inverter DC Link Capacitor Selection Equation (1) https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1604943717643-JB9SO539XPT8XSF4ZALM/eqtn12.png Blog - Inverter DC Link Capacitor Selection Equation (2) https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1604943737274-J0KX1ENNXGWY20741BF8/eqn3.png Blog - Inverter DC Link Capacitor Selection Equation (3) https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1604943746233-D2LCYTUIX3FOUR9A4H86/eqtn14.png Blog - Inverter DC Link Capacitor Selection Equation (4) https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1604943756335-ORYN7TPALAJQ4J7DJFV4/eqtn17.png Blog - Inverter DC Link Capacitor Selection Equation (5) https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1604943766666-PMRA4DTWQTJWB67E430U/image-asset.png Blog - Inverter DC Link Capacitor Selection Equation (6) https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1567969433441-S7KUYJJX5OMOZ24E131R/image-asset.png Blog - Inverter DC Link Capacitor Selection Equation (7) and (8) https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1568162594453-26UPFM6IJE116KVXSJ3Y/modindexvscapProcessed2.png Blog - Inverter DC Link Capacitor Selection Figure 2: Capacitor current normalized to phase current vs modulation index for power factors from 0 - 1.0 https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1604943790981-O2F1UR0BYE889RGO0799/equation+7.PNG Blog - Inverter DC Link Capacitor Selection Equation (9) https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1604943804011-594BL7PG1W7NJ6OJFM62/equation+8.PNG Blog - Inverter DC Link Capacitor Selection Equation (10) https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1568162480826-4PHH6OOLQYSWWBJQW9DQ/image-asset.png Blog - Inverter DC Link Capacitor Selection Figure 3: DC bus voltage ripple peak-to-peak vs. Capacitance https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1568151964735-G14N6Y69QBVFZCP8L552/SimSchematic2.PNG Blog - Inverter DC Link Capacitor Selection Figure 4: Simulation schematic of EV traction system that I use for dimensioning capacitors. Includes parasitics of battery, cable, and dc link capacitor. Component parameters on the left. https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1568151758176-NSBLUMB0LL2NKLFIT3NL/Currents.png Blog - Inverter DC Link Capacitor Selection Figure 5: Plot of phase currents, battery current, and capacitor current. Simulation was ran at base speed - full load conditions with a modulation index of 1. Battery current is entirely DC and capacitor is AC https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1568154951384-OWROE8H9WQMHWX0R1EOY/image-asset.png Blog - Inverter DC Link Capacitor Selection Measured currents and voltage ripple for simulation at full load for 1/4, 1/2, 3/4, and full output frequency https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1568162169179-MQS78ATJKB5K7ZM37CLL/simresults3.PNG Blog - Inverter DC Link Capacitor Selection Figure 5: https://www.specterengineering.com/blog/2018/12/15/dvpampr-for-dummies monthly 0.5 2020-02-17 https://www.specterengineering.com/blog/2018/12/15/power-modules-or-discretes monthly 0.5 2018-12-16 https://www.specterengineering.com/blog/designphilosophy monthly 0.5 2020-11-09 https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1541826869312-6WD2OR262W14CJUJJ9RM/image-asset.jpeg Blog - Specter's Design Philosophy 2018 FSAE vehicle that took home a first place in design. Custom electric motors, quad inverter, and Lithium-Ion high voltage battery pack. PC: Swixeler Photography Services https://www.specterengineering.com/blog/2018/9/23/engineeringdesignprocess monthly 0.5 2020-02-07 https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1581043996079-NLWD6M5K3LR68UNCEINW/Picture1.png Blog - Requirements-Driven System Design Process https://www.specterengineering.com/blog/category/Engineering+Design monthly 0.5 https://www.specterengineering.com/blog/category/Power+Electronics monthly 0.5 https://www.specterengineering.com/blog/tag/Discretes monthly 0.5 https://www.specterengineering.com/blog/tag/ringing monthly 0.5 https://www.specterengineering.com/blog/tag/mosfets monthly 0.5 https://www.specterengineering.com/blog/tag/Engineering+Design monthly 0.5 https://www.specterengineering.com/blog/tag/DVP%26R monthly 0.5 https://www.specterengineering.com/blog/tag/Design+Validation+Plan+and+Report monthly 0.5 https://www.specterengineering.com/blog/tag/silicon+carbide monthly 0.5 https://www.specterengineering.com/blog/tag/Power+Modules monthly 0.5 https://www.specterengineering.com/blog/tag/power+electronics monthly 0.5 https://www.specterengineering.com/blog/tag/Testing monthly 0.5 https://www.specterengineering.com/about daily 0.75 2020-10-19 https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1539746486918-LTVMHYP622BVU518K0GL/DSC_4183.JPG About https://images.squarespace-cdn.com/content/v1/5b9b0eb14611a095d6589969/1540150898472-NTKY514AFUOZU7WAVK7X/IMG-4526-COPY+%282%29.jpg About Jason Sylvestre | CEO https://www.specterengineering.com/privacy-policy daily 0.75 2019-09-18 https://www.specterengineering.com/terms-of-use daily 0.75 2019-09-16 https://www.specterengineering.com/home-1 daily 1.0 2020-11-05