Diodes Incorporated MMSZ5237B-7-F

Overview

MMSZ5237B-7-F from Diodes Incorporated is a 500mW surface-mount Zener diode with a nominal zener voltage of 8.2V (±5% tolerance), 20mA test current, and 8Ω maximum zener impedance at 1kHz. It features SOD123 package, cathode band polarity marking, and is qualified to AEC-Q101 for automotive reliability. It serves as a precision voltage reference or overvoltage clamp in low-power analog and power supply feedback circuits.

For engineers reviewing the MMSZ5237B-7-F datasheet, MMSZ5237B-7-F pinout, MMSZ5237B-7-F application, or MMSZ5237B-7-F equivalent, key selection criteria include zener voltage stability across temperature, low dynamic impedance at 20mA, SOD123 thermal performance on FR-4 PCB, and AEC-Q101 qualification for automotive-grade designs.

Technical Context

This Zener diode operates in reverse breakdown mode to regulate or clamp voltage at 8.2V with ±5% initial tolerance and a typical temperature coefficient of +0.06%/°C (per Figure 6). Its 8Ω zener impedance at 20mA ensures stable regulation under moderate load transients.

The device dissipates up to 370mW at 25°C ambient (derated to 500mW at 75°C lead temperature), with thermal resistance of 338°C/W junction-to-ambient on standard FR-4 layout. Reverse leakage remains ≤3.0μA at 6.5V, supporting low-quiescent-current bias networks.

Key Specifications

Pinout & Package

Two-terminal device in SOD123 package: anode and cathode marked by cathode band on top surface. No internal pin numbering; terminals are unidirectional with polarity critical for correct reverse-bias operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX584-C8V2 and MMBZ5237BS, MMSZ5237B-7-F delivers superior thermal robustness (370mW vs. ≤300mW), lower dynamic impedance (8Ω vs. ≥15Ω), and AEC-Q101 validation-making it the preferred choice for automotive and industrial applications demanding long-term voltage stability under thermal stress.

Availability

MMSZ5237B-7-F is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor interfaces, and consumer power adapter feedback circuits requiring stable component supply and AEC-Q101 compliance.

Supply support for MMSZ5237B-7-F 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

This part belongs to the MMSZ52xxB family of 500mW Zener diodes engineered for general-purpose voltage regulation and protection in automotive, industrial, and consumer electronics where reliability and RoHS compliance are mandatory.

FAQ

What is the maximum reverse leakage current for MMSZ5237B-7-F at 6.5V?

The maximum reverse leakage current is 3.0μA at VR = 6.5V and TA = +25°C, as specified in the Electrical Characteristics table. This value ensures minimal loading in high-impedance reference or bias networks, preserving accuracy in precision analog circuits.

Is MMSZ5237B-7-F suitable for automotive applications?

Yes-it is explicitly qualified to AEC-Q101 standards and marked with "Q" in the ordering code for automotive variants. The commercial version (-7-F) shares identical die and construction; its qualification status is confirmed in DS18010 Rev. 28, Section "Qualification".

How does the SOD123 package affect thermal performance?

When mounted on FR-4 with a 1-inch copper pad, the device achieves 338°C/W junction-to-ambient thermal resistance. Derating begins at +25°C ambient, reaching full 500mW capability only at +75°C lead temperature-critical for thermal design in enclosed enclosures.

What is the zener voltage tolerance and test condition?

The zener voltage is 8.2V with ±5% tolerance (7.79–8.61V), measured at a test current of 20mA and TA = +25°C. This tolerance is guaranteed per production lot and verified during final test using pulsed conditions to minimize self-heating effects.