Littelfuse Announces 800VN-Channel Depletion Mode MOSFET in Modified SOT-223-2L Package

Ideal for power mains applications in industrial, energy, telecommunications, and LED lighting markets


Littelfuse, Inc. (NASDAQ: LFUS), an industrial technology manufacturing company empowering a sustainable, connected, and safer world, is pleased to announce the launch of CPC3981Z, an 800 V, 100 mA, 45 Ohm, Small Power N-Channel Depletion Mode MOSFET.

Compared to a standard SOT-223 package, this new product’s SOT-223-2L package features a removed middle pin. That increases the drain-gate pin spacing from 1.386 millimeters to more than 4 millimeters. The extended creepage distance is beneficial in higher voltage applications such as switch mode power supplies (SMPS) or power factor correction (PFC) startup circuits because designers can avoid the need for costly conformal coating or potting.

The key differentiator of the CPC3981Z is its modified SOT-223-2L package which enables designers to meet the required extended creepage distance for higher voltage applications with a small discrete device. With its larger creepage distance, the CPC3981Z increases circuit robustness and enables cost savings. The 800 V blocking voltage rating of the CPC3981Z makes it the ideal choice for use in industrial, energy, telecommunications, and LED lighting applications, including:

  • Normally ON switches,
  • Power supplies, 
  • Startup circuits,
  • Solid-state relays,
  • Current regulators, and
  • Constant current sources.

The increased distance between the depletion mode MOSFET pins simplifies the isolation management of wide input voltage power supplies and enables compact printed circuit board layouts.

“Littelfuse is proud to offer one of the broadest portfolios of depletion-mode MOSFETs in the industry, and the CPC3981Z further strengthens our position,” said Mark P. Smith, Director of Product Management, Integrated Circuits & MCU at Littelfuse. “This new addition to our low-cost depletion mode MOSFET family, with its new SOT-223-2L package, is an excellent solution for applications that require wide input voltage ranges up to 800 V.”


The CPC3981Z Depletion Mode MOSFETs are available with product order code CPC3981ZTR on tape and reel in quantities of 3,000 pieces per reel. Place sample requests through authorized Littelfuse distributors worldwide. For a listing of Littelfuse distributors, please visit

For More Information
Additional information on the latest series release is available on the Low-Power Depletion Mode MOSFET product page. For further questions, please contact Anne Bauer, Product Manager, at


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