AEC-Q101 qualified bidirectional TVS for 171 V rails
The 1.5SMC200CAHM3_A/I: It clamps at 274 V max from a 171 V reverse standoff, making it a fit for protecting 170 V nominal DC buses or AC lines rectified to that level. It is suited for under-hood or chassis-mounted ECU power inputs, telecom rectifier outputs, and industrial 170 VDC rail clamping where the environment sees -65 °C to 150 °C junction temperature.
Clamping voltage and pulse current profile
The 171 V reverse standoff is the maximum continuous DC voltage the diode blocks without conducting. Breakdown occurs at 190 V min, and the clamping voltage at 5.5 A peak pulse current is 274 V max. For a 170 V rail, the margin between operating voltage and breakdown is about 19 V, which keeps leakage low under normal conditions while still triggering before the rail exceeds the downstream device rating. The 1500 W rating at 10/1000 µs is the standard TVS power metric — a single 1 ms surge at that current level. Real-world energy capability depends on pulse width; shorter transients (e.g. 8/20 µs) allow much higher peak current. The bidirectional configuration means the device clamps equally on positive and negative surges, so a single part protects a bipolar signal pair or an AC-coupled line without needing two diodes back-to-back.
Package and board integration
Housed in a DO-214AB (SMC) package, this is a surface-mount device with a standard footprint shared across the 1.5SMC series. The package is rated for the full 1500 W pulse without derating at 25 °C ambient; above that, follow the power derating curve in the datasheet. Tape-and-reel packaging supports automated pick-and-place assembly. The junction temperature limit of 150 °C means the device can absorb repetitive pulses as long as the average power dissipation keeps the junction below that ceiling.
Sourcing and lifecycle posture
The base product number 1.5SMC200 covers the unidirectional and bidirectional variants in this voltage class. The full suffix — CAHM3_A/I — encodes the bidirectional polarity, the AEC-Q101 automotive grade, and the Vishay Halogen-free / RoHS-compliant build.