Automotive-grade transient voltage suppressor for 14.1 V rails
The STMicroelectronics SM6T16V5CAY is a bidirectional Zener-type TVS diode designed to protect sensitive electronics from voltage transients on automotive power and signal lines. With an AEC-Q101 qualification, it meets the reliability and production requirements of Tier-1 automotive programs. The part clamps a 14.1 V reverse standoff voltage to 29 V maximum during a 136 A (8/20 µs) peak pulse current event, dissipating 600 W of peak pulse power.
For an 8/20 µs waveform the part is rated to handle 136 A peak pulse current, which translates to roughly 3.9 kW peak power during that shorter pulse. This margin lets the designer use a single device on a 14.1 V rail (such as a vehicle's battery line or an ECU power input) without parallel TVS diodes, simplifying the layout. The 29 V clamping voltage ensures downstream 24 V-rated components and 16 V-rated semiconductors stay within their safe operating area during load-dump or inductive kickback events.
For a BOM line that must stay qualified for the next several years, this avoids the supply-chain disruption of an unplanned redesign.
Package and footprint — DO-214AA (SMB) placement
The DO-214AA (SMB) body is a standard surface-mount footprint shared across the SM6T series and many competing TVS families, so it can be dropped into an existing layout without a pad revision. The part is a single bidirectional channel, which eliminates the need to orient the device on the PCB — it protects against transients of either polarity.