SZMMBZ18VALT1G

Overview

The SZMMBZ18VALT1G is a Zener diode manufactured by onsemi, designed for voltage regulation and transient protection. It features a nominal Zener voltage of 18 V with a tight tolerance of ±5%. The device operates in the SOT-23-3 surface-mount package, measuring 2.9 mm in length, 1.3 mm in width, and 1 mm in height. It dissipates up to 225 mW of power at an ambient temperature of 25°C. Key electrical parameters include a maximum reverse leakage current of 100 nA and a Zener impedance of 21 Ohms measured at a test current of 7 mA. The component supports an operating temperature range from -55°C to +150°C and holds AEC-Q100 qualification for automotive reliability.

Feature Summary

• Dual-purpose functionality combining voltage regulation with transient overvoltage and ESD protection capabilities within a single compact package.
• Automotive-grade reliability certified under AEC-Q100 standards, ensuring suitability for mission-critical applications requiring high thermal stability.
• Common anode configuration allows protection of two separate lines using one package, optimizing board space and simplifying circuit design.

Applications

• Voltage regulation in automotive engine control units (ECUs)
• Transient overvoltage and ESD protection for automotive transmission control units
• General purpose voltage reference circuits in industrial electronics

Procurement Notes

Verify the specific suffix 'ALT1G' against the manufacturer's official datasheet to confirm the exact tape and reel packaging quantity and binning specifications. Ensure the procurement order matches the required AEC-Q100 qualification status if deploying in automotive environments. Cross-reference the RoHS compliance documentation provided by onsemi to meet environmental regulations for the target assembly process.

Selection Notes

Select this component when a dual-function solution for voltage clamping and ESD protection is required in space-constrained designs. The 18 V breakdown voltage suits systems operating near this potential. Consider the 225 mW power dissipation limit and the 21 Ohm impedance for precise regulation needs. The SOT-23-3 footprint requires compatible PCB land patterns. Verify that the -55°C to +150°C operating range aligns with the environmental conditions of the final application.

Part Context

This part belongs to the MMBZ18V series of dual common anode Zener diodes. It shares the SOT-23-3 form factor with other members of the family but differs in breakdown voltage and specific electrical characteristics. The series is engineered for high-temperature operation up to +175°C junction temperature, distinguishing it from standard commercial grade diodes. It serves as a specialized alternative to discrete resistor-Zener networks or single-channel TVS diodes.

Replacement Considerations

Direct replacements must match the 18 V Zener voltage, SOT-23-3 package, and AEC-Q100 qualification. Check equivalent parts from other manufacturers such as NXP or STMicroelectronics that offer similar dual common anode configurations. Ensure the replacement maintains the same power dissipation rating and leakage current specifications to avoid circuit performance degradation.