onsemi SZMMSZ5239BT1G

Overview

SZMMSZ5239BT1G from onsemi is a 9.1 V ±5% Zener diode in SOD−123 package, rated for 500 mW power dissipation at TL = 75°C, with 10 Ω dynamic impedance at 20 mA test current and 3 µA reverse leakage at 7 V, used for precision voltage regulation and overvoltage protection in low-power analog circuits.

For engineers reviewing the SZMMSZ5239BT1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal equilibrium performance, junction-to-lead thermal resistance (150 °C/W), ESD robustness (>16 kV HBM), and Pb-free SOD−123 surface-mount compatibility with automated assembly.

Technical Context

This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown at nominal 9.1 V with tight ±5% tolerance under thermal equilibrium conditions (TL = 30°C ±1°C). Its 10 Ω Zener impedance at IZT = 20 mA ensures stable regulation under moderate load transients.

The SOD−123 package provides 150 °C/W junction-to-lead thermal resistance and supports 500 mW dissipation on FR−5 board up to 75°C ambient, derating linearly beyond that point. It features cathode polarity marking and UL 94 V−0 flammability rating.

Key Specifications

Pinout & Package

SOD−123 surface-mount plastic package (1.60 × 2.69 × 1.16 mm), void-free thermosetting case with corrosion-resistant, solderable finish; cathode indicated by band; UL 94 V−0 rated; maximum soldering temperature 260°C for 10 seconds.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener regulation applications.

Compared with MMSZ5239BT1G and BZX84-C9V1, SZMMSZ5239BT1G uniquely combines AEC−Q101 qualification, 500 mW capability, and 10 Ω Zener impedance in SOD−123 - making it the sole option for automotive-compliant, high-stability 9.1 V shunt regulation without footprint redesign.

Availability

SZMMSZ5239BT1G is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor signal conditioning, and medical diagnostic equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SZMMSZ5239BT1G includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

onsemi (Semiconductor Components Industries, LLC) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, and consumer markets.

SZMMSZ5239BT1G belongs to the SZMMSZ52xxxT1G series - engineered for automotive-grade reliability and high-volume surface-mount manufacturing, with focus on voltage reference stability, thermal robustness, and ESD immunity in harsh environments.

FAQ

What is the Zener voltage tolerance of SZMMSZ5239BT1G?

The SZMMSZ5239BT1G has a ±5% Zener voltage tolerance, meaning its nominal 9.1 V breakdown voltage falls between 8.65 V and 9.56 V when measured under thermal equilibrium conditions (TL = 30°C ±1°C) at IZT = 20 mA. This tolerance is confirmed in the "5% TOLERANCE FG ELECTRICAL CHARACTERISTICS" table on page 3 of the official onsemi datasheet for SZMMSZ5239BT1G.

Is SZMMSZ5239BT1G qualified for automotive applications?

Yes, SZMMSZ5239BT1G is AEC−Q101 qualified and PPAP capable, as explicitly stated in the "Features" section of the onsemi datasheet. The "SZ" prefix denotes compliance with automotive-specific site and control change requirements, distinguishing it from the commercial-grade MMSZ5239BT1G variant. This makes SZMMSZ5239BT1G suitable for under-hood and cabin electronics where reliability and process traceability are mandatory.

What is the maximum power dissipation of SZMMSZ5239BT1G on a standard PCB?

SZMMSZ5239BT1G is rated for 500 mW total power dissipation on an FR−5 board at lead temperature (TL) of 75°C, with linear derating of 6.7 mW/°C above that temperature. This rating assumes use of the minimum recommended footprint and is validated per onsemi's thermal measurement methodology using infrared scanning, as detailed in the "MAXIMUM RATINGS" table on page 1 of the datasheet.

Does SZMMSZ5239BT1G have ESD protection, and what level is specified?

SZMMSZ5239BT1G features an ESD rating of Class 3 (>16 kV) per the Human Body Model (HBM), as documented in the "Features" section of the onsemi datasheet. This high-level ESD robustness is intrinsic to the device structure and does not require external protection circuitry, making SZMMSZ5239BT1G suitable for handling in standard manufacturing environments and deployment in systems exposed to frequent operator contact.

What package type and dimensions does SZMMSZ5239BT1G use?

SZMMSZ5239BT1G uses the SOD−123 surface-mount package (Case 425, Style 1), measuring 1.60 mm × 2.69 mm × 1.16 mm. The package features a cathode band marking, Pb-free construction, UL 94 V−0 flammability rating, and is optimized for automated board assembly. Mechanical details are provided in the "MECHANICAL CASE OUTLINE" diagram on page 6 of the onsemi datasheet.