Zener Diodes
A Zener Diode is a specialized semiconductor device engineered to maintain a stable reference voltage in circuits by operating reliably in its reverse breakdown region. Unlike standard diodes (which break down destructively under reverse bias), Zener diodes leverage controlled reverse breakdown for precise voltage regulation, surge protection, and signal clipping.
Core Working Principle:
1. Reverse Breakdown Mechanism:
Zener Effect: Dominates below 5.6V – quantum tunneling of electrons across the PN junction.
Avalanche Effect: Dominates above 5.6V – impact ionization creating electron "avalanches".
→ Both maintain near-constant voltage (VZ) across the diode during reverse conduction.
2.Self-Recovery:
Unlike fuses or MOVs, Zener diodes revert to blocking mode when voltage drops below VZ.
Part Number
Marking
Package
PD
W
Vz @ Izt
Nom.
(V)
Min.
(V)
Max.
(V)
ZZT
Max.
(Ω)
@ Izt
(mA)
ZZK
Max.
(Ω)
@ Izk
(mA)
IR(μA)
Max.
@VR
(V)