Automotive-grade bidirectional TVS for 48V rail clamping
The 1.5SMC56CAHM3_A/H is a bidirectional Zener-type TVS diode from Vishay's 1.5SMC series, built on the TransZorb® technology. It is qualified to AEC-Q101, meaning it meets the automotive reliability stress and temperature requirements for under-hood and cabin electronics. This makes it a fit for protecting 48 V nominal automotive buses, telecom line cards, or industrial DC supplies from transients like load dump or inductive kickback.
Voltage ratings and what they mean for the rail
The breakdown voltage (VBR) range starts at 53.2 V minimum, which is the point where the device begins to conduct significantly. The clamping voltage (VC) is 77 V maximum at the rated peak pulse current of 19.5 A. This is the voltage the protected circuitry sees during a surge event; a downstream component rated for 80 V or higher has margin. The 1500 W peak pulse power rating means the device can absorb a single 10/1000 µs surge up to that energy level without failing.
This simplifies the BOM and saves board space on a 48 V bus that sees surges of either polarity.