51 V Zener, 5 W — DO-214AA SMB
The SMBJ5369BE3/TR13 is a 51 V Zener diode rated for 5 W continuous power dissipation in the DO-214AA (SMB) surface-mount package. The 51 V nominal voltage suits it for voltage regulation, overvoltage clamping, or reference circuits in power supplies and industrial controls. Tolerance is ±5%, which covers most general-purpose regulation needs without the cost of tighter-binned parts. The 27 Ω maximum Zener impedance (Zzt) means the regulation slope is moderate — expect a few hundred millivolts of variation across the operating current range.
Package and thermal fit
The DO-214AA (SMB) footprint is a standard JEDEC outline for 5 W Zener diodes. Reverse leakage is specified at 500 nA maximum at 36.7 V reverse voltage — that is well below the knee, so the diode draws negligible current in the off state. Forward voltage is 1.2 V maximum at 1 A, typical for a Zener in this power class.