Diodes Incorporated MMSZ5252BQ-7-F

Overview

MMSZ5252BQ-7-F from Diodes Incorporated is an automotive-grade 24 V ±5% Zener diode in SOD123 package, rated for 500 mW power dissipation at TL = +75°C and 370 mW at TA = +25°C, with 33 Ω typical zener impedance at 5.2 mA test current and 0.1 µA reverse leakage at 18 V. It serves as a precision voltage reference and overvoltage clamp in automotive body control modules.

For engineers reviewing the MMSZ5252BQ-7-F datasheet, MMSZ5252BQ-7-F pinout, MMSZ5252BQ-7-F application, or MMSZ5252BQ-7-F equivalent, key selection criteria include zener voltage tolerance (±5%), thermal resistance (338 °C/W), AEC-Q101 qualification, SOD123 footprint compatibility, and low leakage (<0.1 µA @ VR = 18 V).

Technical Context

This Zener diode operates in reverse breakdown mode to maintain stable 24 V regulation across temperature and current variations. Its 33 Ω dynamic impedance at IZT = 5.2 mA ensures minimal voltage deviation under load transients, while the −0.04 %/°C temperature coefficient (typical for 24 V devices in this series) limits drift over −65°C to +150°C operating range.

The device uses alloy 42 leadframe with matte tin plating, enabling reliable solderability per MIL-STD-202 Method 208. Its SOD123 package features UL 94V-0 molding compound, moisture sensitivity level 1, and cathode band polarity marking - all aligned with automotive assembly and reliability requirements.

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 × D × A); weight ≈ 0.01 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C24LT1G and 1N4749A, MMSZ5252BQ-7-F delivers automotive-grade reliability in a compact SOD123 package with lower thermal resistance than SOT-23 and tighter leakage than DO-41, making it optimal for space-constrained, high-reliability 24 V systems.

Availability

MMSZ5252BQ-7-F is available at Aetrix Electronics and suitable for automotive body control modules, industrial 4–20 mA transmitters, infotainment power sequencing, and LED driver overvoltage protection requiring stable component supply and AEC-Q101 compliance.

Supply support for MMSZ5252BQ-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, specializing in high-reliability components for automotive, industrial, and computing markets.

MMSZ5252BQ-7-F belongs to the MMSZ52xxB automotive Zener diode family, engineered specifically for robust voltage regulation and transient suppression in harsh-environment 12 V/24 V vehicle electrical systems.

FAQ

What is the maximum continuous power dissipation for MMSZ5252BQ-7-F at ambient temperature?

The device is rated for 370 mW continuous power dissipation at TA = +25°C when mounted on an FR-4 PCB with 1 inch² copper pad. Derating begins linearly above +25°C at 3.0 mW/°C, reaching 500 mW only at lead temperature TL = +75°C - which requires direct thermal coupling to a heatsink or large copper plane.

How does the zener impedance affect regulation accuracy in a 24 V reference circuit?

With ZZT = 33 Ω at 5.2 mA, a ±10 mA load variation causes ±0.33 V output shift - critical for precision references. For sub-10 mV stability, designers must limit dynamic current swing or add post-regulation filtering; the low 0.1 µA IR further minimizes error in high-impedance bias networks.

Is MMSZ5252BQ-7-F compatible with lead-free reflow profiles?

Yes - the matte tin finish over alloy 42 leadframe is qualified for standard Pb-free reflow (J-STD-020, peak 260°C). The SOD123 package withstands three reflow cycles without delamination, and its moisture sensitivity level 1 eliminates bake requirements prior to assembly.

Can this Zener diode replace a 24 V TVS for ESD or load dump protection?

No - MMSZ5252BQ-7-F is not rated for surge energy absorption. While it clamps at ~24 V, its 500 mW rating limits single-pulse capability to <10 mJ. For load dump (ISO 7637-2 Pulse 5a, up to 120 V/400 ms), a dedicated TVS like SMAJ24A is required; this Zener serves only steady-state regulation and low-energy transients.