Littelfuse 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, defence systems, eVTOL platforms, and other mission-critical designs requiring high power, high reliability, and stringent screening.
Designed in a compact SPD4-1 surface-mount package, the new series delivers 15kW or 30kW peak pulse dissipation capability (10/1000μs) 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 behaviour, 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 characterisation 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
Key features and benefits
- Up to 15 or 30kW peak pulse power absorption for lightning and high-energy surge protection
- 30kV 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 reflows 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
- Defence/aerospace power distribution modules
- High-reliability industrial and transportation platforms requiring lightning surge immunity
FAQs: Learn more about these high-reliability TVS diodes.
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What applications benefit most from these TVS diodes?
They are optimised 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.
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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 defence qualification environments.
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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.
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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.
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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.
