onsemi SZMMSZ4704T3G

Overview

SZMMSZ4704T3G from onsemi is a 17 V ±5% Zener diode in SOD−123 package, rated for 500 mW power dissipation at 75°C, with 50 µA test current (IZT), 0.05 µA leakage at 12.9 V reverse bias, and −55°C to +150°C operating temperature range-used for precision voltage reference and overvoltage protection in automotive power management circuits.

For engineers reviewing the SZMMSZ4704T3G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, low IZT stability, AEC−Q101 qualification, thermal derating behavior, and SOD−123 board assembly compatibility.

Technical Context

This device operates as a two-terminal voltage reference diode with sharp reverse breakdown at nominal 17 V, specified under 50 µA test current and 25°C ambient. Its dynamic impedance is ≤35 Ω at 1 mA, and temperature coefficient is +3.5 mV/°C near 17 V, enabling stable regulation across automotive thermal environments.

The SOD−123 package provides 150°C/W junction-to-lead thermal resistance and supports automated placement. It features Class 3 ESD rating (>16 kV HBM), Pb−free construction, and UL 94 V−0 flammability compliance-meeting requirements for space-constrained, high-reliability automotive PCBs.

Key Specifications

Pinout & Package

SZMMSZ4704T3G is housed in a surface-mount SOD−123 plastic package (1.60 × 2.69 × 1.16 mm), void-free thermosetting case with corrosion-resistant, solderable finish and cathode polarity band marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMSZ4704T3G and BZX84-C16LT1G, SZMMSZ4704T3G uniquely combines AEC−Q101 qualification, 500 mW power capability in SOD−123, and 0.05 µA leakage-making it the sole option for automotive-grade 17 V clamping where both reliability and thermal margin are critical.

Availability

SZMMSZ4704T3G is available at Aetrix Electronics and suitable for automotive power management, industrial sensor calibration, and LED driver protection requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for SZMMSZ4704T3G 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 focused on energy-efficient electronics for automotive, industrial, cloud, and IoT applications.

SZMMSZ4xxxT3G series was developed specifically for AEC−Q101-compliant automotive subsystems requiring robust, low-leakage Zener regulation in space-constrained SOD−123 packaging.

FAQ

What is the Zener voltage tolerance of SZMMSZ4704T3G?

The SZMMSZ4704T3G has a Zener voltage specification of 16.15 V (minimum), 17.0 V (nominal), and 17.85 V (maximum) at IZT = 50 µA and TA = 25°C-resulting in a ±5% tolerance band. This tight tolerance ensures predictable clamping behavior in automotive voltage rails where deviation beyond ±5% could trigger false fault detection or compromise downstream IC operation. The SZMMSZ4704T3G maintains this spec across its qualified temperature range.

Is SZMMSZ4704T3G qualified for automotive applications?

Yes, SZMMSZ4704T3G is AEC−Q101 qualified and PPAP capable, with validation for temperature cycling, humidity testing, and mechanical shock per automotive reliability standards. The "SZ" prefix explicitly denotes compliance with automotive site and control change requirements. Unlike standard MMSZ4704T3G, the SZMMSZ4704T3G undergoes additional process controls and lot-level traceability required for Tier 1 automotive supply chains.

What is the maximum power dissipation of SZMMSZ4704T3G at 100°C ambient?

SZMMSZ4704T3G is rated for 500 mW at TL = 75°C, with linear derating of 6.7 mW/°C above that temperature. At 100°C lead temperature, its maximum power dissipation is 500 mW − (100 − 75) × 6.7 mW = 332.5 mW. This value assumes proper PCB copper area per the FR−5 board definition (3.5 × 1.5 inches, minimum footprint). Actual performance depends on thermal interface design, and the SZMMSZ4704T3G must not exceed its 150°C junction limit.

Does SZMMSZ4704T3G have a specified dynamic impedance?

While the datasheet does not list a guaranteed maximum dynamic impedance (ZZT) for SZMMSZ4704T3G at 17 V, Figure 5 shows typical ZZT ≈ 35 Ω at IZ = 1 mA and TJ = 25°C for 17 V nominal devices in the series. This value reflects small-signal AC impedance under regulation and directly impacts ripple rejection in reference applications. For designs requiring guaranteed ZZT, engineers should consult onsemi's characterization reports or validate empirically at the target operating current.

How is polarity indicated on the SZMMSZ4704T3G package?

SZMMSZ4704T3G uses a cathode band marking on the SOD−123 case to indicate Pin 1 (cathode); the unmarked end is the anode (Pin 2). This polarity band aligns with JEDEC-standard SOD−123 orientation and is visible under magnification or automated optical inspection. Correct orientation is critical-reverse installation prevents Zener action and may cause open-circuit failure in clamp configurations. The SZMMSZ4704T3G marking code "DP" appears adjacent to the band per page 3 of the datasheet.