The MM1W91 Zener Diodes from Microdiode Electronics are SOD-123FL RoHS compliant silicon planar power zener diode with an encapsulated resin body in a single 3-pin SOD-123FL package. It is used for voltage referencing, overvoltage protection, and clamping applications. The device has a breakdown voltage of 1.9V, an operating temperature range of -55°C to +150°C, an average forward current of 1A, a maximum reverse current of 2µA, and peak current of 2.5A. It also features good temperature stability and high-current capability.