15V rail clamp for automotive and industrial 12V systems
The SMAJ15AQ-13-F is a unidirectional TVS diode from Diodes Incorporated, part of the SMAJ series, designed to protect 15V DC power rails from transient overvoltage events. Its 15V reverse standoff voltage means it sits transparently on a nominal 12V or 15V supply bus, drawing negligible leakage current until a surge pushes the line above its 16.7V minimum breakdown threshold. At that point it clamps the transient to 24.4V maximum, shunting up to 16.4A of peak pulse current away from the downstream circuitry. The -55°C to 150°C operating junction temperature range covers under-hood automotive ambient and industrial enclosure heat, so the clamping performance holds across the full thermal envelope.
AEC-Q101 qualification and automotive deployment
The SMAJ15AQ-13-F carries AEC-Q101 qualification, the automotive-grade stress test standard for discrete semiconductors. This means each device has passed temperature cycling, high-temperature reverse bias, and ESD sensitivity screening per the Automotive Electronics Council requirements. It is intended for use in engine control units, body controllers, infotainment power supplies, and any 12V vehicle bus that must survive ISO 7637-2 transients. Production status is Active, so the part is still in current manufacture by Diodes Incorporated.
DO-214AC SMA footprint and board integration
Housed in the DO-214AC (SMA) surface-mount package, the SMAJ15AQ-13-F shares a standard footprint with thousands of other TVS diodes and Schottky rectifiers. The SMA body measures approximately 4.6 mm x 2.8 mm with a low profile, making it suitable for dense PCB layouts in automotive ECU and industrial control boards. The single unidirectional channel protects one rail per device. For bidirectional or dual-rail protection, two devices or a different part number from the SMAJ series would be needed.