onsemi MMSZ5244BT1

Overview

MMSZ5244BT1 from ON Semiconductor is a 5% tolerance, 14 V nominal Zener voltage regulator diode in SOD−123 surface-mount package, rated for 500 mW power dissipation on FR−5 board at 75°C, with 9.0 mA test current (IZT), 15 Ω dynamic impedance (ZZT), and 0.1 µA reverse leakage at 10 V (VR). It serves as a precision voltage reference or overvoltage clamp in low-power analog circuits, power supply feedback loops, and ESD-protected sensor interfaces.

For engineers reviewing the MMSZ5244BT1 datasheet, pinout, applications, or equivalent options, key selection criteria include its ±5% Zener voltage tolerance, thermal equilibrium–specified VZ, 16 kV HBM ESD rating, and compatibility with automated SMT assembly on high-density PCBs.

Technical Context

This device operates as a two-terminal silicon Zener diode, conducting in reverse breakdown to maintain stable voltage across its terminals under specified IZT conditions. Its Zener voltage is characterized with junction in thermal equilibrium at TL = 30°C ±1°C, ensuring repeatable regulation independent of transient thermal gradients.

It exhibits a typical temperature coefficient of +5.5 mV/°C near 14 V, enabling predictable drift compensation in temperature-sensitive references. The SOD−123 package provides low thermal resistance (RJL = 150°C/W) and supports reflow soldering up to 260°C for 10 seconds without degradation.

Key Specifications

Pinout & Package

The MMSZ5244BT1 is housed in a Pb-free SOD−123 plastic surface-mount package (Case 425, Style 1), measuring 2.84 mm × 1.35 mm × 0.94 mm (L × W × H), with cathode indicated by a polarity band.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX584-C14 and MMSZ5244ET1G, the MMSZ5244BT1 offers optimal balance of power capability (500 mW), regulation stiffness (15 Ω ZZT), and voltage accuracy (±5%) in the widely adopted SOD−123 footprint-making it preferred for industrial and automotive feedback and reference designs requiring reliability and manufacturability.

Availability

MMSZ5244BT1 is available at Aetrix Electronics and suitable for automotive sensor modules, industrial power supplies, consumer overvoltage protection circuits, and medical signal conditioning systems requiring stable component supply and long-term sourcing continuity.

Supply support for MMSZ5244BT1 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The MMSZ52xxxT1G series was designed for general-purpose, medium-current Zener regulation in space-constrained surface-mount applications-emphasizing manufacturability, ESD robustness, and thermal stability across extended temperature ranges.

FAQ

What is the Zener voltage tolerance of the MMSZ5244BT1?

The MMSZ5244BT1 has a ±5% Zener voltage tolerance, meaning its nominal 14 V rating spans 13.3 V to 14.7 V at IZT = 9.0 mA and thermal equilibrium. This tolerance is confirmed in the "5% TOLERANCE FG ELECTRICAL CHARACTERISTICS" table on page 3 of the ON Semiconductor datasheet. The "B" suffix explicitly denotes this 5% grade, distinguishing it from ±2% ("C") or ±10% ("E") variants in the same family. MMSZ5244BT1 performance remains within these bounds across its full operating temperature range.

Does the MMSZ5244BT1 meet automotive qualification standards?

Yes, the SZ-prefix variant (SZMMSZ5244BT1G) is AEC−Q101 qualified and PPAP capable, meeting automotive reliability requirements. While the standard MMSZ5244BT1 is not explicitly AEC−Q101 certified, it shares identical die, packaging, and process with the SZ version-differing only in traceability and control documentation. Both versions operate across −55°C to +150°C and feature 16 kV HBM ESD protection, making MMSZ5244BT1 suitable for non-safety-critical automotive applications such as cabin sensors and body electronics where full AEC−Q101 documentation is not mandated.

What is the maximum reverse leakage current for the MMSZ5244BT1 at 10 V?

The MMSZ5244BT1 exhibits a maximum reverse leakage current (IR) of 0.1 µA at VR = 10 V, as specified in the Electrical Characteristics table on page 3 of the datasheet. This low leakage supports high-impedance bias networks and precision reference applications where parasitic current paths must be minimized. The value is measured at TA = 25°C and reflects worst-case behavior under standard test conditions; actual leakage decreases further at lower temperatures and increases modestly at elevated junction temperatures.

Can the MMSZ5244BT1 be used in place of the MMSZ5244CT1G?

No-the MMSZ5244BT1 and MMSZ5244CT1G are not interchangeable without design review. The MMSZ5244BT1 has ±5% Zener voltage tolerance (13.3–14.7 V), while the MMSZ5244CT1G has tighter ±2% tolerance (13.7–14.3 V). Their Zener impedances also differ: 15 Ω vs. 8.5 Ω respectively. Using MMSZ5244BT1 in a circuit designed for the "C" variant may cause regulation error beyond acceptable limits, especially in precision feedback loops. Always verify voltage window and dynamic impedance requirements before substitution. MMSZ5244BT1 is not a drop-in replacement for MMSZ5244CT1G.

What is the thermal resistance from junction to lead (RJL) for the MMSZ5244BT1?

The thermal resistance from junction to lead (RJL) for the MMSZ5244BT1 is 150°C/W, as listed in the Maximum Ratings table on page 2 of the datasheet. This parameter quantifies how effectively heat transfers from the silicon junction to the PCB copper via the leads, directly impacting safe operating area under continuous DC bias. Combined with RJA = 340°C/W, RJL confirms the SOD−123 package's suitability for moderate-power regulation when mounted on standard FR−5 board with recommended footprint-enabling reliable 500 mW operation at TL = 75°C without forced cooling.