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Wolfspeed Announces the Lucid Air is Using its SiC Power Modules

April 27, 2022 by Ian Hahn

Wolfspeed will manufacture its XM3 silicon carbide (SiC) modules at its just-opened 200 mm fab in upstate New York, the largest in the world, for use in the new luxury electric vehicle’s inverters.

With a wicked fast charger and industry leading range and efficiency, per EPA estimates, the all-electric Lucid Air from auto manufacturer Lucid Motors has been making waves. 

MotorTrend named it 2022’s car of the year; InsideEVs confirmed they have tested no onboard charger as quick as the Air’s Wunderbox; and in late March, ROHM announced that its SiC power MOSFETs are a lynchpin of the box’s architecture. 

Now, Wolfspeed has joined the fray. On Monday, coinciding with the opening of its 200 mm Mohawk Valley SiC fab in Marcy, New York—which Wolfspeed says is the first and largest of its kind, anywhere—the company announced that the Lucid Air’s inverters feature its XM3 power modules. 

 

A Lucid Air cuts the ribbon at the opening of Wolfspeed's Mohawk Valley fab. Image used courtesy of Governor Kathy Hocul

 

Below, we take a deep dive into the module itself, and how it makes the Lucid Air’s motor purr. 

 

The EAB450M12XM3 — Wolfspeeds’s Power Module 

Wolfspeed’s EAB450M12XM3, the newest edition to its four-member XM3 family, is an automotive-qualified, 1200 V, 450 A SiC half-bridge module. Taking advantage of the low switching losses enjoyed by SiC power devices, the module will provide the driving power for the Lucid Air’s absurdly light 163-lb, 670-hp (500 kW) electric motor.

 

The Lucid Air's electric motor, broken down here, is absurdly light. Screenshot used courtesy of Lucid Motors

 

The new module, which is housed in a package measuring 80 x 53 x 19 mm, commands only half the weight and volume of standard 62 mm module devices, thus maximizing power density, a critical consideration in electric vehicle (EV) design. While operating at a full 450 A, the unit features typical RDS(ON)s of only 2.6 mΩ, increasing to 4.6 mΩ only at 175 ℃. 

The device is built on a highly reliable, silicon nitride (Si3N4) power substrate, which allows the unit to operate at a full 175 ℃ junction temperature on a continuous basis. Mechanical robustness is also assured, even under the harsh conditions characteristic of the automotive environment. 

 

Standout Technical Features

The EAB450M12XM3 sports a number of standout technical features, chief among them its terminal layout. The layout allows for direct bus bar connection without bends or bushings, enabling a simple, low-inductance design with 6.7 nH specified between the V+ and V- terminals.

 

The EAB450M12XM3. Screenshot used courtesy of Wolfspeed

 

In addition, isolated integrated temperature sensing assures high-level temperature protection, and dedicated drain Kelvin pins enable direct voltage sensing.

 

Other Design-verified Maximums

Gate source (g-s) voltage for the EAB450N12XM3 is +19 to -8 V (transient, 200 ns or less). The module’s maximum pulsed current is 900 A. 

 

Additional Electrical Characteristics (per MOSFET position)

Characteristics are typical values unless otherwise noted, and are subject to further conditions enumerated in the datasheet.

  • G-S threshold: 2.5 V 
  • Zero gate voltage drain current: 5 μA (typ) 500 μA (max)
  • Turn-On switching energy: 11 mJ 
  • Turn-Off switching energy: 10.1 mJ 
  • Internal gate resistance: 2.5 Ω
  • Input capacitance: 38 nF
  • Output capacitance: 1.5 nF
  • g-s charge: 355 nC
  • g-d (gate to drain) charge: 500 nC
  • Total gate charge: 1330 nC

 

Body Diode Characteristics (per MOSFET position)

Characteristics are typical values unless otherwise noted, and are subject to further conditions enumerated in the datasheet.

  • Body diode forward voltage: 4.7 V
  • Reverse recovery time: 52 ns
  • Reverse recovery charge: 6.6 µC
  • Peak reverse recovery current: 195 A
  • Reverse recovery energy: 0.2 mJ

 

Applications

Whether inside or outside the Lucid Air, the EAB450M12XM3 is generally suited for use in motor drives, traction drives, DC fast chargers, and automotive testing equipment. 

 

Getting to Market Faster

Wolfspeed offers the KIT-CRD-CIL12N-XM3, an evaluation tool for both engineers who are new to SiC and experienced designers who’d like to familiarize themselves with the EAB450M12XM3.

 

The KIT-CRD-CIL12N-XM3. Image used courtesy of Wolfspeed

 

The evaluation kit is also relevant to the three additional members of Wolfspeed’s XM3 Module platform.

 

Gary Elinoff contributed technical research and writing. Feature image used courtesy of Lucid Motors