onsemi SZMMSZ5250ET1G

Overview

SZMMSZ5250ET1G from onsemi is a 20 V ±5% Zener diode in SOD-123 package, rated for 500 mW power dissipation at 75 °C on FR-5 board, with 6.2 mA test current, 25 Ω dynamic impedance at I_ZT, and 0.1 µA leakage at 15 V reverse bias. It serves as a precision voltage reference or overvoltage clamp in low-power analog sensing and power rail stabilization circuits.

For engineers reviewing the SZMMSZ5250ET1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance (±5%), thermal resistance (340 °C/W junction-to-ambient), ESD rating (>16 kV HBM), peak surge capability (225 W @ 8 × 20 µs), and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This device operates as a two-terminal silicon Zener diode with sharp reverse breakdown at nominal 20 V, designed for stable voltage regulation under DC or low-frequency transient conditions. Its 25 Ω Zener impedance at 6.2 mA ensures minimal output voltage variation with load current changes, while the 0.1 µA leakage at VR = 15 V supports low-power standby operation.

The SOD-123 package enables automated placement in high-density PCB layouts, with cathode polarity marked by a band and thermal performance validated per JEDEC JESD51-1 (infrared scan method). Junction temperature range spans −55 °C to +150 °C, supporting operation in extended industrial and automotive environments.

Key Specifications

Pinout & Package

SOD-123 surface-mount plastic package (1.60 × 2.69 × 1.16 mm), void-free thermosetting case with corrosion-resistant finish, UL 94 V-0 flammability rating, and cathode indicated by polarity band.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX584C20 and MMSZ4702T1G, SZMMSZ5250ET1G delivers superior thermal performance (340 °C/W vs. ~400 °C/W), lower Zener impedance (25 Ω vs. ≥30 Ω), and verified AEC-Q101 compliance - making it the preferred choice for automotive and high-reliability industrial voltage reference applications.

Availability

SZMMSZ5250ET1G is available at Aetrix Electronics and suitable for automotive sensor modules, industrial analog input protection circuits, and low-power battery monitoring systems requiring stable component supply and long-term lifecycle support.

Supply support for SZMMSZ5250ET1G 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 (formerly ON Semiconductor) is a global semiconductor supplier delivering energy-efficient power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

SZMMSZ5250ET1G belongs to the AEC-Q101-qualified SZMMSZ52xxET1G series, engineered specifically for automotive-grade voltage reference and transient suppression in harsh-environment electronic control units.

FAQ

What is the Zener voltage tolerance of SZMMSZ5250ET1G?

SZMMSZ5250ET1G has a nominal Zener voltage of 20 V with a standard tolerance of ±5%, meaning its actual breakdown voltage falls between 19.0 V and 21.0 V when measured at 6.2 mA test current and thermal equilibrium at 30 °C. This tolerance is guaranteed across the full operating temperature range and is critical for precision reference applications where tight voltage margins are required.

Is SZMMSZ5250ET1G qualified for automotive applications?

Yes, SZMMSZ5250ET1G is AEC-Q101 qualified and PPAP capable, with manufacturing and testing performed under automotive-specific quality controls. The "SZ" prefix explicitly denotes compliance with automotive requirements, including extended temperature operation (−55 °C to +150 °C), enhanced ESD robustness (>16 kV HBM), and process change notification protocols - making SZMMSZ5250ET1G suitable for engine control, ADAS, and body electronics.

What is the maximum power dissipation for SZMMSZ5250ET1G on a standard PCB?

SZMMSZ5250ET1G is rated for 500 mW total power dissipation on an FR-5 board at lead temperature (T_L) of 75 °C, with linear derating of 6.7 mW/°C above that temperature. This rating assumes the minimum recommended footprint per onsemi's packaging specification and does not apply to bare die or non-standard thermal pads - actual dissipation must be validated using board-specific thermal simulation or measurement.

How is polarity identified on the SZMMSZ5250ET1G package?

SZMMSZ5250ET1G uses a cathode band marking on the SOD-123 case to indicate polarity: Pin 1 (banded end) is the cathode, and Pin 2 (non-banded end) is the anode. This marking aligns with JEDEC standard orientation and is visible under 20× magnification; correct orientation is essential for proper reverse-bias operation during Zener regulation or transient clamping.

Does SZMMSZ5250ET1G have Pb-free construction?

Yes, SZMMSZ5250ET1G is manufactured in a Pb-free (RoHS-compliant) configuration, as indicated by the "G" suffix and documented in onsemi's Pb-Free Packaging Strategy. It meets JEDEC J-STD-609A Class 3 moisture sensitivity level and supports standard reflow profiles up to 260 °C for 10 seconds - enabling compatibility with modern lead-free assembly processes without compromising reliability.