4.7 V Zener — thermal and tolerance budget
The SMAJ4732E3/TR13 is a 4.7 V Zener diode rated for 2 W continuous power dissipation in the DO-214AC (SMA) surface-mount package. The ±10% tolerance on the nominal voltage means the actual zener voltage across a reel of parts falls between 4.23 V and 5.17 V at the test current — a factor to account for when setting a shunt regulator's output or a protection clamp's threshold.
Package and reflow compatibility
Supplied in Tape & Reel packaging, this part is ready for automated pick-and-place assembly. The DO-214AC (SMA) footprint is a standard JEDEC outline with a single cathode-band polarity mark — the pad layout matches the common SMA diode land pattern, so no footprint adjustment is needed for most designs. At the 2 W power limit, junction temperature rise must be calculated against the board's copper area and airflow — a 2 W Zener on a standard FR-4 pad without thermal vias can exceed 150°C junction in still air.