USCi
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SiC Transistor

The breakthrough United Silicon Carbide xJ series of 1200V JFET's are the industry's lowest RDS(on) SiC transistor device. This market milestone for silicon carbide enables best in class converter and inverter system efficiency through incorporating the lowest figure of merit (FOM) switch commercially available. The depletion mode xJ JFET series takes advantage of silicon carbide's significantly superior performance over silicon, offering the user the best wide bandgap switch at standard 175°C Tj max. When appropriately packaged, the xJ series is capable of operating at temperatures of 250°C and beyond.

The xJ series is targeted for use in power conversion circuits where efficiency counts. Applications such as high-end Server and Telecom SMPS, PC Silver box and solar inverters all demand the performance of SiC JFET's to meet the latest efficiency standards and regulations, with motor drives, uninterruptible power supplies (UPS), electrical vehicle (EV) and other consumer AV markets all embracing the SiC advantage.

xJ Series JFET selector guide

Part Number
Package
V
RDS(on)
Id max
Data Sheet
SPICE Model
UJN1205K TO247 1200V 45mO 38A PDF file  (PDF) LIB file  (TXT)
UJN1205Z Die 1200V 45mO 38A PDF file  (PDF) LIB file  (TXT)
UJN1208K TO247 1200V 80mO 21A PDF file  (PDF) LIB file  (TXT)
UJN1208Z Die 1200V 80mO 21A PDF file  (PDF) LIB file  (TXT)

PDF file 1200V xJ SiC series reliability documentation (PDF)

PDF file xJ Series JFET's – designer guide (PDF)

PDF file TO247 Package, marking and tape & reel / tube information (PDF)

Device Features:

  • Improved Figure of Merit (RDS(on) x Qg)
  • Voltage controlled
  • 175°C Tj max in plastic package , 250°C Tj max as die
  • Temperature independent switching behavior
  • Low gate charge
  • Low intrinsic capacitance

System Benefits:

  • Increased efficiency compared to silicon and silicon carbide equivalent switches
  • Low gate drive losses
  • Highly stable switching performance across all thermal design points
  • Reduced cooling requirements
  • Capable of running at higher switching speeds which reduces BOM count and costs

The most dramatic JFET advantage over silicon is that the total Figure of Merit (RDS(on) x Qg) is significantly reduced hence lowering both JFET switching loss and conduction loss to increase overall system efficiency. Also unlike SiC MOSFET's where the Tjmax is limited to 175°C, the JFET threshold is stable hence allowing operating temperatures >250°C. Figure 1 shows a complete UJN1205K switching cycle with Vds of 800V and Id of 20A taken at 25°C operation and repeated at 250°C operation. It can be clearly seen that operating temperature has no real impact on switching rise times and fall times.

800V, 200 A, 0.5 mH Inductor

USCi xJ series SiC JFET's delivers the lowest RDS(on) SiC transistor available in the market. Designed to achieve best in class system efficiency, improved thermal characteristics and industry leading FOM – the xJ series enable the most efficient switching solutions for both power discrete and power module applications.