Diodes Incorporated MMSZ5243BS-7

Overview

MMSZ5243BS-7 from Diodes Incorporated is a surface-mount silicon Zener diode with a nominal zener voltage of 13 V, ±5% tolerance (12.35–13.65 V), 200 mW power dissipation, and 13 Ω zener impedance at 9.5 mA test current. It features SOD-323 package, cathode band polarity marking, and is rated for operation from –65 °C to +150 °C. It serves as a precision voltage reference or overvoltage clamp in low-power analog signal conditioning circuits.

For engineers reviewing the MMSZ5243BS-7 datasheet, MMSZ5243BS-7 pinout, MMSZ5243BS-7 application, or MMSZ5243BS-7 equivalent, key selection criteria include zener voltage accuracy at 9.5 mA, low dynamic impedance under regulation, thermal resistance (625 °C/W), reverse leakage (<0.5 µA at 9.9 V), and compatibility with automated SMT assembly on FR-4 PCBs.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain stable voltage across its terminals when biased above its specified zener voltage. Its planar die construction ensures consistent breakdown characteristics and low leakage, while the SOD-323 package enables high-density placement and thermal performance suitable for space-constrained consumer and industrial PCBs.

The device is characterized at 25 °C with a 9.5 mA test current (IZT), exhibits 600 Ω maximum knee impedance (ZZK) at 0.25 mA, and maintains <0.5 µA reverse leakage (IR) at VR = 9.9 V - confirming tight regulation capability in low-current biasing applications such as sensor reference rails or microcontroller reset supervision.

Key Specifications

Pinout & Package

Package: SOD-323 - ultra-small plastic surface-mount case (2.30–2.70 mm length × 1.20–1.40 mm width × 0.25–0.35 mm height), UL 94V-0 rated, moisture sensitivity level 1, cathode indicated by band marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX584C13 and MMBZ5243BS, MMSZ5243BS-7 provides optimal balance of compact SOD-323 size, 200 mW rating, and low 13 Ω impedance - making it preferred for high-density, low-power reference and clamp roles where footprint and leakage are critical.

Availability

MMSZ5243BS-7 is available at Aetrix Electronics and suitable for industrial sensor reference, microcontroller reset circuitry, USB-C power negotiation clamp, and LED current regulation requiring stable component supply and full RoHS compliance.

Supply support for MMSZ5243BS-7 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.

The MMSZ52xxBS series belongs to Diodes' general-purpose Zener diode product line, engineered for precision voltage regulation and transient suppression in cost-sensitive, high-volume consumer, computing, and industrial applications.

FAQ

What is the maximum reverse leakage current for MMSZ5243BS-7 at 9.9 V?

The maximum reverse leakage current (IR) is 0.5 µA at VR = 9.9 V, measured at 25 °C ambient. This value is confirmed in the Electrical Characteristics table of DS31038 Rev. 13–2 and reflects the device's ability to minimize standby current in high-impedance reference circuits.

Can MMSZ5243BS-7 be used in place of MMSZ5242BS (12 V) or MMSZ5245BS (15 V)?

No - MMSZ5243BS-7 has a distinct 13 V nominal zener voltage (12.35–13.65 V range). Substituting it for 12 V or 15 V variants would shift regulation points outside design tolerances, potentially causing incorrect sensor scaling or premature reset assertion. Voltage-specific selection is mandatory.

What is the recommended PCB pad layout for SOD-323 mounting?

Diodes Incorporated specifies pad dimensions in Application Note AP02001 (available at diodes.com/datasheets/ap02001.pdf): 0.5 mm pad width, 1.2 mm pad length, 0.3 mm solder mask opening, and 0.4 mm spacing between pads. This layout ensures reliable reflow soldering and thermal performance per JEDEC J-STD-020D.

Does MMSZ5243BS-7 meet halogen- and antimony-free "Green" requirements?

Yes - it complies with Diodes Incorporated's "Green" definition: <900 ppm bromine, <900 ppm chlorine (<1500 ppm total Br + Cl), and <1000 ppm antimony compounds. This is documented in Notes 2 and 3 of DS31038 and verified via material declarations.