SiC JFETs – The ideal circuit protection solution

The UJ3N series are high-performance SiC normally-on JFET transistors with options ranging from 650V to 1700V. This series exhibits ultra-low on resistance (RDS(ON)), as low as 25mΩ, and low gate charge (QG) allowing for low conduction and reduced switching loss. The device normally-on characteristics with low RDS(ON) at VGS = 0 V is also ideal for current protection circuits without the need for active control.  The devices are also commonly used in series connection with a Si-MOSFET as robust ‘supercascodes’, which give all the advantages of wide band-gap technology with very high operating voltages and easy gate drive.


  • 650/900/1200/1700 V device options
  • Low on-resistance: RDS(on) maximum of 25mΩ
  • Current limiting: rapid current decrease due to self-heating, limiting I2t
  • Normally-on JFETs: VG(th) invariant with temperature
  • Peak TJ > 600°C

SiC JFET Selector Guide

Part Number Package V RDS(on) typ Id max
ID New Part Number Package V RDS(on) typ Id max Data Sheet SPICE Model Buy Now
12 UJ3N120070K3S TO-247-3L 1200 70 33.5 Order Online
13 UJ3N120035K3S TO-247-3L 1200 35 63.0 Order Online
14 UJ3N065080K3S TO-247-3L 650 80 32.0 Order Online
15 UJ3N065025K3S TO-247-3L 650 25 85.0 Order Online
19 UF3N090800* Wafer 900 735 4.2 Contact Sales
17 UF3N170400* Wafer 1700 400 8.0 Contact Sales
18 UF3N120140* Wafer 1200 140 20.0 Contact Sales
20 UF3N090350* Wafer 900 330 8.4 Contact Sales
21 UF3N065600* Wafer 650 580 5.6 Contact Sales
22 UF3N065300* Wafer 650 265 10.0 Contact Sales

* – Idmax Limited by bondwires

  1. UJN products have reached end-of-life, see below. Please contact sales for support regarding these products.
  2. For all die inquiries, contact

Design Resources

Full Product Selector Guide

Part Number Decoder

Reliability & Package Data

Normally-On JFET limits current flow from a surge event

Ability to handle TJ > 600ºC

Back-to-back normally-on JFETs support bidirectional current limiting


Low series resistance, excellent current limiting behavior

Normally-on JFETs create self-powered two-terminal fast acting circuit breakers


High Side Switch (DC Breaker)


Reliability & Package Data


Marking and tape & reel / tube information


Qualification Report

Part Number Decoder

Translate Part Numbers

Stay Informed