Littelfuse expands its high-reliability TVS diode portfolio with compact SPD4-1 surface-mount devices engineered for avionics, military, and other mission-critical systems requiring robust transient protection.
ROSEMONT, Ill, March 31, 2026 -- Littelfuse, Inc. (NASDAQ: LFUS), an industrial technology manufacturing company shaping solutions for the safe and efficient transfer of electrical energy, today announced the release of the SM15KPA-HR/HRA and SM30KPA-HR/HRA High-Reliability Transient Voltage Suppressor (TVS) Diode Series. These new devices are engineered to provide superior lightning-induced transient protection for avionics, aviation electronics, defense systems, eVTOL platforms, and other mission-critical designs requiring high power, high reliability, and stringent screening. (View the video in English, Chinese & Japanese)
Designed in a compact SPD4-1 surface-mount package, the new series delivers 15 kW or 30 kW peak pulse dissipation capability (10/1000 μs) while supporting full SMT pick-and-place assembly—an advantage over legacy high-power axial devices. Both families offer fast response time (<1 ps), excellent clamping behavior, low incremental surge resistance, and stable operation over a –55 °C to 150 °C junction temperature range.
The SM15KPA-HR/HRA and SM30KPA-HR/HRA Series are among the few high-power, high-reliability SMT TVS diodes specifically developed for avionics, offering protection up to RTCA/DO-160 Waveform 5A Level 5 lightning surge compliance. Screening includes 100% surge testing, high-temperature storage, temperature cycling, X-ray inspection, HTRB testing, and final electrical characterization in accordance with MIL-STD-750.
“These new high-power TVS diodes in a surface-mount package give avionics system designers the performance margins they need while supporting standard SMT automatic pick-and-place assembly,” said Charlie Cai, Director of Product Management, Protection Business, SBU. “They provide superior protection for high-reliability applications without the size, weight, or assembly constraints of traditional solutions.”
Differentiating the Four Versions
| Series | Peak Pulse Power Rating | Reverse Standoff Voltage | Minimum Breakdown Voltage | Group B Tests |
|---|---|---|---|---|
| SM15KPA-HR | 15 kW | 20 - 400 V | 22.3 - 444 V | Included |
| SM15KPA.HRA | 15 kW | 20 - 400 V | 22.3 - 444 V | Not Included |
| SM30KPA.HR | 30 kW | 28 - 400 V | 31.1 - 444 V | Included |
| SM30KPA.HRA | 30 kW | 28 - 400 V | 31.1 - 444 V | Not Included |
Key Features and Benefits
- Up to 15 kW or 30 kW peak pulse power absorption for lightning and high-energy surge protection
- 30 kV ESD data line protection per IEC 61000-4-2
- Superior clamping capability and low incremental surge resistance
- Fast response time (<1 ps) for sensitive circuit protection
- High temperature reflow capability (245 °C / 10 s)
- Matte-tin, RoHS-compliant construction
- Whisker-tested per JEDEC JESD201A
- DO-160 Waveform 5A Level 5 protection capability
Target Markets and Applications
- Avionics flight computers and controllers
- Navigation, communication, and radar electronics
- eVTOL propulsion and battery management systems
- Defense/aerospace power distribution modules
- High-reliability industrial and transportation platforms requiring lightning surge immunity
FAQs: Learn more about these high-reliability TVS diodes.
- What applications benefit most from these TVS diodes?
They are optimized for avionics, eVTOL, military, and other mission-critical platforms where lightning-induced transients and high-energy surge events must be tightly controlled. Their high-power density and robust screening make them ideal for safeguarding I/O lines, power buses, and sensitive navigation or communication electronics.
- How do the HR and HRA versions differ?
Both meet high-reliability 100% screening tests, but the HR versions include the enhanced MIL-STD-750 Group B tests that ensure additional test rigor, and extended reliability margins suited for the most demanding aerospace and defense qualification environments.
- Why choose a surface-mount (SMT) high-power TVS device?
The SPD4-1 SMT package supports automated assembly, reduces weight and board space, and eliminates the need for through-hole mounting traditionally associated with high-energy TVS components—an advantage in modern avionics hardware.
- Do these devices meet DO-160 lightning surge requirements?
Yes. The series provides protection up to DO-160 Waveform 5A Level 5, making them well-suited for aircraft electronics that must withstand severe transient environments.
- Are both unidirectional and bidirectional versions available?
Yes. All four series offer uni- and bidirectional polarity options, allowing engineers to match the device type to the signal or power rail being protected.
Availability
The SM15KPA-HR/HRA and SM30KPA-HR/HRA Series TVS diodes are available in tape and reel format in quantities of 500. Sample requests are accepted through authorized Littelfuse distributors worldwide. For a listing of Littelfuse distributors, please visit Littelfuse.com.
For More Information
Additional information is available on the SM15KPA-HR/HRA and SM30KPA-HR/HRA TVS Diode Series product pages. For technical questions, please contact: Charlie Cai, Director of Product Management, Protection Business, SBU, CCai@littelfuse.com.
About Littelfuse
Littelfuse, Inc. (NASDAQ: LFUS) is an industrial technology manufacturing company shaping solutions for the safe and efficient transfer of electrical energy. Across more than 20 countries, and with approximately 16,000 global associates, we partner with customers to design and deliver innovative, reliable solutions. Serving over 100,000 end customers, our products are found in a variety of industrial, transportation, and electronics end markets–everywhere, every day. Learn more at Littelfuse.com.