1500W bidirectional TVS for 70V rails
The SMCJ70CA-13-F is a 1500W bidirectional TVS diode from Diodes Incorporated, designed to clamp transients on 70V nominal rails. The bidirectional channel protects both polarities from a single device, saving board space and reducing BOM count compared to back-to-back unidirectional parts.
Clamping parameters that define the protection window
The reverse standoff voltage is 70V — the rail voltage this TVS lets pass under normal operation. Breakdown occurs at a minimum of 77.8V, and clamping is specified at 113V maximum with a peak pulse current of 13.3A. That 113V clamp is the let-through voltage the downstream circuitry must survive; a 70V-rated rail with a 20% margin sees about 84V, so the 113V clamp gives roughly 35% headroom above the rail — typical for a TVS protecting a 70V bus from transients up to 1500W.
The SMC body is larger than the smaller SMA/SMB siblings, which is necessary to dissipate the 1500W pulse without exceeding the 150°C junction temperature limit. The wide operating temperature range from -55°C to 150°C covers industrial control cabinets, automotive under-hood environments, and outdoor telecom equipment without derating concerns.