Diodes Incorporated MMSZ5250BQ-7-F

Overview

MMSZ5250BQ-7-F from Diodes Incorporated is an automotive-grade 20V Zener diode in SOD123 package, rated for 500mW power dissipation at TL=+75°C and 370mW at TA=+25°C, with 6.2mA test current, 25Ω zener impedance at 1kHz, and maximum 0.1μA reverse leakage at 15V. It serves as a precision voltage reference or overvoltage clamp in automotive power supply regulation circuits.

For engineers reviewing the MMSZ5250BQ-7-F datasheet, MMSZ5250BQ-7-F pinout, MMSZ5250BQ-7-F application, or MMSZ5250BQ-7-F equivalent, this page provides verified electrical parameters, AEC-Q101 qualification status, thermal derating behavior, SOD123 mechanical dimensions, and automotive tape-and-reel packaging details essential for board-level design and production validation.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain stable 20V regulation across a 6.2mA test current, with temperature coefficient optimized for mid-range Zener voltages (≈+0.06%/°C per Figure 6). Its 25Ω dynamic impedance at 1kHz ensures low AC ripple under moderate load transients.

The device uses a planar epitaxial construction with cathode band polarity marking, qualified to AEC-Q101 for high-reliability automotive use. Thermal resistance is 338°C/W junction-to-ambient on FR-4 PCB with 1-inch copper pad, requiring derating above +25°C per Figure 1.

Key Specifications

Pinout & Package

Two-terminal device in SOD123 package: anode and cathode marked by molded cathode band. Dimensions: 2.65mm width × 3.65mm length × 1.05mm height (max), with 0.57mm lead pitch and matte tin-plated Alloy 42 leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX584C20-Q-TP and 1N4744A, MMSZ5250BQ-7-F uniquely combines AEC-Q101 qualification, SOD123 SMT compatibility, and 500mW pulse capability-making it optimal for new automotive electronics requiring zero-defect reliability and automated manufacturing.

Availability

MMSZ5250BQ-7-F is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor interfaces, infotainment power sequencing, and medical diagnostic equipment requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for MMSZ5250BQ-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 automotive Zener diode product line, engineered specifically for high-reliability voltage regulation and transient suppression in 12V/24V automotive electrical systems.

FAQ

What is the maximum allowable power dissipation for MMSZ5250BQ-7-F at +105°C ambient?

At +105°C ambient, the device must be derated per Figure 1: linear derating begins at +25°C with slope −3.7mW/°C. From 370mW at +25°C, reduction is (105−25)×3.7 = 296mW, leaving 74mW maximum continuous dissipation. This assumes standard FR-4 PCB with 1-inch copper pad layout.

Does MMSZ5250BQ-7-F have a specified capacitance value?

No capacitance value is specified in DS18010 Rev. 28. Figure 4 shows typical total capacitance ≈15pF for 20V Zeners, but Diodes Incorporated does not guarantee or characterize C_T for this part. Designers requiring controlled capacitance should verify with bench measurement or select a part with published C_T specs.

How is the cathode identified on the SOD123 package?

The cathode is marked by a distinct molded black band encircling the cathode-end of the SOD123 case. Per DS18010 page 2, "Polarity: Cathode Band" - this band aligns with the cathode terminal in top-view orientation shown in the package outline diagram.

Can MMSZ5250BQ-7-F replace MMSZ5250B-7-F in existing designs?

Yes, MMSZ5250BQ-7-F is the automotive-qualified version of MMSZ5250B-7-F, sharing identical electrical characteristics and SOD123 mechanical form. The "Q" suffix denotes AEC-Q101 qualification and green compound; both use same Zener voltage, impedance, and leakage specs, making them functionally interchangeable where automotive reliability is required.