Protection window and clamping behaviour
The SMAJ8.5CA-13-F: Breakdown occurs at 9.44V minimum, meaning the device starts clamping before the voltage exceeds the 8.5V standoff by about 11%. The single bidirectional channel replaces two unidirectional TVS diodes wired in anti-series, saving board area and reducing the parts count.
Package, footprint and thermal integration
Housed in the DO-214AC (SMA) package, the SMAJ8.5CA-13-F uses the standard surface-mount footprint for this power class — the same pad layout as a typical SMB or SMC device with a smaller body. The supplier device package is also designated SMA, so the land pattern matches the industry-standard SMA solder pad geometry. The -55°C to +150°C junction temperature range covers military and industrial thermal environments; the 400W peak pulse rating is derated linearly above 25°C per the datasheet curve, so the effective pulse power at 85°C ambient drops to roughly 280W. The low leakage at standoff voltage (not listed but typical for this Zener family) keeps the quiescent drain negligible on battery-powered lines.
The base product number is SMAJ8.5, so other package variants (SMB, SMC) or unidirectional versions in the same family share the same silicon and are parametric drop-ins for different power levels. Available through independent distribution channels; pricing and lead time are confirmed at RFQ against the BOM quantity.