Automotive-grade 400 W bidirectional TVS in a DO-214AC footprint
The SMAJ13CAQ-13-F: This places it in the same qualification tier as components used in engine control units, body controllers, and sensor modules under the hood. The DO-214AC (SMA) package is a standard surface-mount footprint for TVS diodes up to 600 W. The small body and gull-wing leads suit automated pick-and-place assembly, and the copper pad area under the cathode tab sets the thermal impedance — a larger pad reduces junction temperature rise during repetitive surges.
Clamping voltages and the protection window
This 21.5 V clamp is the voltage the downstream circuitry must survive — a 24 V-rated IC has margin; a 16 V-rated capacitor does not. The bidirectional configuration means a single device protects both positive and negative transients — useful on signal lines that swing below ground or on AC-coupled interfaces. No polarity marking needed during placement. The 150°C junction limit covers under-hood ambient plus self-heating during a surge event. Derating the peak pulse power above 25°C is standard — at 125°C the 400 W rating typically drops to about 60% of the 25°C value, per the manufacturer's derating curve.
Active production and sourcing posture
The Tape & Reel packaging is the standard shipping format for this surface-mount part, typically supplied in 5,000-piece reels.