It is a bidirectional device with a single protection channel, designed to clamp transients on 33.3V nominal rails. The breakdown voltage range starts at 37.1V min, and the clamping voltage at the peak pulse current of 11.2A is 53.9V max. The 260pF capacitance at 1MHz is typical for this power class and package.
Automotive grade and temperature range
This part carries the Automotive, AEC-Q101 series designation, meaning it has passed the stress and reliability tests required for automotive electronic systems.
onsemi lists the P6SMB39CAT3 as Obsolete. No official last-time-buy date or successor has been published on this record. The DO-214AA SMB package is widely used, so a pin-compatible alternative from the same or another manufacturer may be a cleaner long-term fix.
The SMB footprint is common and reflow-compatible with standard lead-free profiles. The bidirectional construction means no polarity marking on the body — orientation is not critical for placement.