onsemi SZMMSZ5238BT1G

Overview

SZMMSZ5238BT1G from onsemi is a 500 mW, ±5% tolerance Zener diode in SOD−123 package, with nominal reverse breakdown voltage of 8.7 V at 20 mA test current, dynamic impedance of 8 Ω at I_ZT, and leakage current ≤0.25 µA at 6.5 V reverse bias - used for precision voltage regulation and overvoltage protection in low-power analog sensor interfaces and microcontroller reset circuits.

For engineers reviewing the SZMMSZ5238BT1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal equilibrium operation at TL = 30°C, junction-to-lead thermal resistance (150°C/W), ESD robustness (>16 kV HBM), and Pb-free SOD−123 footprint compatibility with automated assembly.

Technical Context

This device operates as a two-terminal voltage reference diode, conducting in reverse bias above its specified Zener voltage (8.27–9.14 V) with tightly controlled dynamic impedance (600 Ω max at I_ZK = 0.25 mA) and low temperature coefficient (±3.5 mV/°C typical near 8.7 V). It is characterized under thermal equilibrium conditions (TL = 30°C ±1°C) per onsemi's Zener theory guidelines.

The SZMMSZ5238BT1G meets AEC−Q101 qualification for automotive applications and supports stable regulation across −55°C to +150°C junction temperature range. Its SOD−123 package enables high-density PCB layouts while maintaining 500 mW power dissipation on FR−5 board at T_L = 75°C, derated linearly above that point.

Key Specifications

Pinout & Package

SZMMSZ5238BT1G uses the SOD−123 surface-mount plastic package (Case 425, Style 1), measuring 1.60 × 2.69 × 1.16 mm, with cathode indicated by a polarity band. The package is void-free, transfer-molded, UL 94 V−0 rated, and Pb-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMSZ5238BT1G, SZMMSZ5238BT1G adds automotive-grade process controls and PPAP support without altering electrical performance; versus BZX84-C8V2LT1G, it delivers tighter voltage stability, higher power capability, and superior thermal performance in a smaller footprint.

Availability

SZMMSZ5238BT1G is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, and microcontroller reset circuits requiring stable component supply, long-term lifecycle assurance, and AEC−Q101-compliant sourcing.

Supply support for SZMMSZ5238BT1G 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.

SZMMSZ5238BT1G belongs to the SZMMSZ52xxxT1G series - a family of AEC−Q101-qualified Zener diodes engineered specifically for automotive subsystems and high-reliability industrial control where voltage reference stability, thermal resilience, and process traceability are mandatory.

FAQ

What is the nominal Zener voltage and tolerance of SZMMSZ5238BT1G?

The nominal Zener voltage of SZMMSZ5238BT1G is 8.7 V with a ±5% tolerance, meaning the actual measured voltage falls between 8.27 V and 9.14 V when tested at I_ZT = 20 mA under thermal equilibrium conditions (TL = 30°C ±1°C). This tolerance is confirmed in the onsemi datasheet Table 3 for "B" suffix devices and applies directly to SZMMSZ5238BT1G as part of the SZMMSZ52xxBT1G series.

Is SZMMSZ5238BT1G qualified for automotive applications?

Yes, SZMMSZ5238BT1G is AEC−Q101 qualified and PPAP capable, as explicitly stated in the onsemi datasheet features section. The "SZ" prefix denotes automotive-grade manufacturing controls, site-specific change management, and extended reliability testing - making SZMMSZ5238BT1G suitable for production automotive electronics including body control modules, lighting drivers, and sensor signal conditioning.

What is the maximum power dissipation and thermal derating behavior of SZMMSZ5238BT1G?

SZMMSZ5238BT1G has a maximum power dissipation of 500 mW on FR−5 board at lead temperature (T_L) = 75°C, derating linearly at 6.7 mW/°C above that point. Its junction-to-lead thermal resistance is 150°C/W, allowing accurate thermal modeling in PCB layouts where copper area and airflow are constrained - critical for reliable operation in sealed enclosures or high-ambient environments.

How does the dynamic impedance of SZMMSZ5238BT1G affect voltage regulation performance?

SZMMSZ5238BT1G exhibits a maximum dynamic impedance (Z_ZT) of 8 Ω at I_ZT = 20 mA, which directly determines how much the output voltage varies with changes in load current. Lower Z_ZT means tighter regulation - for example, a 10 mA load shift causes only ~80 mV deviation in clamped voltage, supporting stable references in precision analog circuits where SZMMSZ5238BT1G is commonly deployed.

What packaging and marking details apply to SZMMSZ5238BT1G?

SZMMSZ5238BT1G is supplied in Pb-free SOD−123 package (Case 425, Style 1), marked with "F3" code and date code per onsemi's generic marking diagram. The cathode is identified by a band at Pin 1; dimensions are 1.60 × 2.69 × 1.16 mm. It ships in tape-and-reel format (3,000 units/reel), compatible with standard pick-and-place equipment and reflow soldering up to 260°C for 10 seconds.