Active AEC-Q101 TVS for automotive transient protection
The Bourns 1.5SMBJ18CA-H is an active-production bidirectional Zener TVS diode in the 1.5SMBJ series, qualified to AEC-Q101 for automotive-grade reliability.
Parametric envelope and clamp performance
The 18 V reverse standoff voltage (working voltage) means the diode stays transparent on a nominal 12 V or 18 V rail, only clamping when the line exceeds the 20 V minimum breakdown threshold. A single bidirectional channel protects both polarities of a differential signal pair or AC-coupled line without needing two diodes back-to-back. The -55°C to 150°C junction temperature range covers the full automotive under-hood ambient, with derating above 25°C per the standard power-temperature curve.
Package and board integration
Housed in the DO-214AA (SMB) surface-mount package, the 1.5SMBJ18CA-H uses the standard JEDEC footprint for automated pick-and-place and reflow assembly. The SMB body size (approx 4.6 mm x 3.6 mm) fits dense PCB layouts, and the copper pad area under the cathode tab should follow the recommended land pattern to manage thermal impedance during repetitive pulse events.
Sourcing and compliance posture
As an AEC-Q101 qualified device, the part carries automotive-grade documentation including PPAP-level traceability and RoHS/REACH compliance data from Bourns. No power line protection rating (per the spec) confirms this is a signal-line TVS, not intended for AC mains or high-energy industrial power bus clamping.