BZX79-C39.133 is a 3.9 Volt, 133 mW Zener Diode from NXP. It is designed for use as a voltage reference or clamp in electronic circuits, particularly in low-voltage, low-power applications. It has an operating temperature range of -40 to +125°C, a reverse leakage current of 1 µA at 3.9V, and a breakdown voltage of 3.86V. The diode features the high-reliability planar glass passivation die construction to ensure long-term reliability and stability.