Diodes Incorporated MMSZ5250B-7-F

Overview

MMSZ5250B-7-F from Diodes Incorporated is a 20 V, 500 mW surface-mount Zener diode in SOD123 package, rated for 6.2 mA test current with 25 Ω zener impedance at 1 kHz and maximum 0.1 µA reverse leakage at 15 V, widely used for voltage regulation and reference in power supply feedback loops and overvoltage protection circuits.

For engineers reviewing the MMSZ5250B-7-F datasheet, MMSZ5250B-7-F pinout, MMSZ5250B-7-F application, or MMSZ5250B-7-F equivalent, key selection criteria include nominal zener voltage tolerance (±5%), thermal resistance (338 °C/W), RoHS-compliant green molding compound, AEC-Q101 qualification, and SOD123 footprint compatibility with automated PCB assembly.

Technical Context

This Zener diode operates in reverse breakdown to maintain stable voltage across its terminals under varying load and line conditions. Its 20 V nominal zener voltage exhibits a positive temperature coefficient of +0.07 %/°C, and it delivers regulated output within ±5% tolerance over the full operating temperature range of –65 °C to +150 °C.

The device is optimized for medium-current regulation up to 6.2 mA test current, with low dynamic impedance (25 Ω) ensuring minimal voltage deviation during transient load changes. Its SOD123 package supports high-density layouts and meets J-STD-020 moisture sensitivity Level 1 requirements for reflow compatibility.

Key Specifications

Pinout & Package

Package: SOD123 - Surface-mount plastic case with cathode band marking; dimensions: 2.65 mm × 1.55 mm × 1.05 mm (L × W × H); weight ≈ 0.01 g; matte tin-plated alloy 42 leadframe; UL 94V-0 flammability rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX584C20LT1G and MMBZ5250BS-7-F, MMSZ5250B-7-F offers superior thermal performance (338 °C/W vs. ≥400 °C/W) and higher power handling (370 mW vs. 300 mW), making it more suitable for sustained regulation in industrial and automotive power domains.

Availability

MMSZ5250B-7-F is available at Aetrix Electronics and suitable for switch-mode power supplies, overvoltage protection circuits, industrial sensor references, and automotive body control modules requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for MMSZ5250B-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 the Americas.

MMSZ5250B-7-F belongs to the MMSZ52xxB series of general-purpose Zener diodes engineered for cost-effective, high-reliability voltage regulation in commercial and automotive applications with stringent environmental compliance requirements.

FAQ

What is the maximum continuous reverse current this Zener can handle at 20 V?

At 20 V, the maximum continuous reverse current is limited by power dissipation: 370 mW ÷ 20 V = 18.5 mA at +25°C ambient. Derating applies per Figure 1 - at +75°C ambient, max current drops to ~11.3 mA due to 500 mW limit at T_L = +75°C and thermal resistance constraints.

Is MMSZ5250B-7-F suitable for use in automotive infotainment power rails?

Yes - it is AEC-Q101 qualified and rated for –65 °C to +150 °C operation, supporting under-hood and dashboard environments. Its 20 V zener voltage provides margin above typical 12 V/24 V rail transients, and its green halogen-free construction meets Tier 1 automotive material compliance standards.

How does the SOD123 package affect PCB layout and thermal performance?

The SOD123 package requires a 0.95 mm × 4.05 mm recommended pad layout (per Diodes Inc. guidelines) to ensure solder joint reliability and thermal conduction. Its 338 °C/W junction-to-ambient resistance demands at least a 1-inch² copper pour for full 370 mW operation; smaller pads reduce safe operating current proportionally.

Can this Zener be used as a voltage reference for ADC biasing in precision analog circuits?

It can serve as a coarse reference in non-critical applications, but its ±5% tolerance, +0.07 %/°C tempco, and 25 Ω impedance make it unsuitable for high-accuracy ADC biasing. For such use, dedicated voltage references (e.g., REF3020) with ppm-level stability and µV-level noise are recommended instead.