onsemi SZMMSZ4V3T1G

Overview

SZMMSZ4V3T1G from onsemi is a 4.3 V ±5% Zener voltage regulator diode in SOD−123 package, rated for 500 mW power dissipation at 75°C, with 90 Ω dynamic impedance at 5 mA test current and 3 µA max reverse leakage at 3.3 V, used for precision voltage reference and overvoltage protection in automotive power rails.

For engineers reviewing the SZMMSZ4V3T1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance (±5%), thermal resistance (340°C/W), AEC−Q101 qualification, ESD rating (>16 kV HBM), and SOD−123 board assembly compatibility.

Technical Context

This device operates as a two-terminal shunt regulator, maintaining stable output voltage across varying load currents by conducting excess current to ground when input exceeds V_Z. It exhibits a temperature coefficient of approximately +2.2 mV/°C near 4.3 V, enabling predictable drift compensation in bias networks.

Designed for surface-mount use on FR−4/FR−5 PCBs, it supports automated placement and reflow soldering up to 260°C for 10 seconds. Its cathode-anode polarity is marked by a band, and its 1.60 × 2.69 × 1.16 mm footprint enables high-density layout in space-constrained automotive and industrial modules.

Key Specifications

Pinout & Package

SOD−123 surface-mount package: 2-lead, 1.60 × 2.69 × 1.16 mm, void-free thermosetting plastic case with corrosion-resistant finish; cathode identified by polarity band.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMSZ4V3T1G and BZX84-C4V3, SZMMSZ4V3T1G delivers automotive-grade reliability, tighter thermal performance (340°C/W R_JA), and superior ESD immunity-making it the sole choice for safety-critical voltage clamping where AEC−Q101 traceability and zero-layout change are mandatory.

Availability

SZMMSZ4V3T1G is available at Aetrix Electronics and suitable for automotive power management, industrial sensor signal conditioning, and low-power IoT voltage supervision requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SZMMSZ4V3T1G 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, medical, and IoT applications.

SZMMSZ4V3T1G belongs to the AEC−Q101-qualified SZMMSZxxxT1G Zener regulator family, engineered specifically for robust voltage reference and transient suppression in harsh-environment automotive electronics.

FAQ

What is the Zener voltage tolerance of SZMMSZ4V3T1G?

The SZMMSZ4V3T1G has a nominal Zener voltage of 4.3 V with a standard tolerance of ±5%, resulting in a guaranteed range of 4.09 V to 4.52 V at I_ZT = 5 mA and T_A = 25°C. This tolerance is specified per the onsemi datasheet revision 13 and applies to all units in the production lot, supporting consistent design margins in voltage-clamp circuits.

Is SZMMSZ4V3T1G suitable for automotive applications?

Yes, SZMMSZ4V3T1G is AEC−Q101 qualified and PPAP capable, with full traceability and process controls meeting automotive quality standards. Its −55°C to +150°C junction temperature range, >16 kV HBM ESD rating, and SOD−123 package reliability make it approved for use in engine control, body electronics, and ADAS subsystems where regulatory compliance is mandatory.

What is the maximum power dissipation for SZMMSZ4V3T1G at 100°C ambient?

At T_A = 100°C, SZMMSZ4V3T1G's power dissipation is derated from 500 mW using the 6.7 mW/°C slope above 75°C. This yields 500 mW − (100 − 75) × 6.7 mW = 332.5 mW maximum continuous power. Thermal design must ensure junction temperature remains ≤150°C under worst-case load and airflow conditions.

How does the temperature coefficient affect SZMMSZ4V3T1G performance?

SZMMSZ4V3T1G exhibits a positive temperature coefficient of approximately +2.2 mV/°C near its 4.3 V operating point, meaning its Zener voltage increases linearly with temperature. This behavior is documented in Figure 1 of the onsemi datasheet and enables predictable bias-point tracking in temperature-compensated reference circuits without additional components.

Can SZMMSZ4V3T1G replace MMSZ4V3T1G in an existing design?

Yes, SZMMSZ4V3T1G is a direct functional and mechanical replacement for MMSZ4V3T1G, sharing identical electrical specifications, SOD−123 package dimensions, and pinout. The only difference is the SZ prefix indicating AEC−Q101 qualification and enhanced process controls-no PCB or schematic changes are needed when upgrading for automotive compliance.