Littelfuse Launches AK-FL Series FlatSuppressX™ TVS Diodes for Aviation Power Systems
Littelfuse, Inc. has announced the AK-FL Series FlatSuppressX™ TVS Diodes, a line of axial-leaded transient voltage suppression diodes. These devices are engineered to safeguard high-voltage DC aviation power systems from transient overvoltage events. They are designed to deliver a flat, low, and stable clamping voltage, which helps prevent latch-up in solid-state power controller (SSPC) modules and other high-voltage semiconductor devices critical to aviation power systems.
The introduction of the AK-FL Series addresses a critical design challenge emerging with the adoption of higher-voltage 270 V–800 V DC power architectures in aviation and eVTOL platforms. Engineers require transient protection that can tightly limit clamping voltage to prevent latch-up while maintaining the surge robustness necessary for high-voltage power applications. The AK-FL Series meets this demand through Littelfuse's proprietary FlatSuppressX™ technology.
FlatSuppressX technology utilizes an advanced foldback/snapback I-V characteristic to ensure a near-constant, low clamping voltage during both fast transients and high-energy surge events. This characteristic is crucial for protecting sensitive power electronics and meeting the stringent requirements of modern aviation power distribution. Unlike conventional TVS devices, which can exhibit higher and less predictable clamping voltages as surge current increases, FlatSuppressX devices precisely control the transient response, thereby mitigating the risk of latch-up.
This controlled clamping response offers significant design flexibility, allowing engineers to select lower voltage-rated semiconductors in high-voltage power circuits, which can enhance design efficiency without compromising protection. The AK-FL Series extends the proven FlatSuppressX platform, previously used in automotive systems, into high-voltage avionics applications. The series is available with surge current ratings of 6 kA, 8 kA, and 10 kA at an 8/20 µs waveform. Each device is up-screened per MIL-STD-750 test methods to ensure the high reliability required for avionics and supports RTCA DO-160 environmental qualification requirements. The devices come in an axial-leaded package that is halogen-free, RoHS-compliant, and Pb-free E4 terminated, supporting both reflow and wave soldering.
Specifications
| Product | Surge Current Ratings | Surge Test Waveform | Supported DC Architecture | Screening | Environmental Qualification | Package |
|---|---|---|---|---|---|---|
| AK-FL Series FlatSuppressX™ TVS Diodes | 6 kA, 8 kA, and 10 kA | 8/20 µs | 270 V–800 V DC | 100% screened per MIL-STD-750 methods | RTCA DO-160 | Axial-leaded, halogen-free, RoHS-compliant, Pb-free E4 terminated |
Key Features
- Utilizes FlatSuppressX™ technology with an advanced foldback/snapback I-V characteristic.
- Maintains a flat, low, and stable clamping voltage during transient events.
- Designed to prevent latch-up in SSPC modules and other high-voltage semiconductor devices.
- Offers three surge current ratings: 6 kA, 8 kA, and 10 kA.
- Surge current ratings are specified at an 8/20 µs waveform.
- Ensures a near-constant, low clamping voltage during fast transients and high-energy surge events.
- Enables the use of lower voltage-rated semiconductors in high-voltage power circuits.
- Up-screened per MIL-STD-750 test methods for avionics applications.
- Supports RTCA DO-160 environmental qualification requirements.
- Features an axial-leaded package that is halogen-free, RoHS-compliant, and Pb-free E4 terminated.
- The package supports both reflow and wave soldering.
- Represents the first FlatSuppressX™ TVS diode series from Littelfuse designed for aviation and eVTOL power protection.
Applications
- Aerospace and defense 270 V–800 V DC aviation power trains.
- Solid-state power controller (SSPC) circuits.
- eVTOL and next-generation aircraft electrical systems.
- DC power rail protection in high-reliability avionics.
- High-voltage aviation power systems requiring transient overvoltage protection.
- High-voltage aviation power circuits containing sensitive semiconductor devices requiring precise clamping control.
Avalaibility
The AK-FL Series FlatSuppressX™ TVS Diodes are available in bulk packaging, with quantities of 56 pieces per box. Littelfuse is accepting sample requests through its authorized distributors worldwide, providing customers with access to samples for evaluation of the series in aviation and eVTOL power protection applications. The AK-FL Series is designed for high-voltage DC aviation power systems and offers 6 kA, 8 kA, and 10 kA surge current ratings at 8/20 µs.
