Diodes Incorporated MMBZ5241BW-7

Overview

MMBZ5241BW-7 from Diodes Incorporated is a 11 V, 200 mW surface-mount Zener diode in SOT323 package, rated for ±5% zener voltage tolerance (10.45–11.55 V at 20 mA), with 22 Ω dynamic impedance at test current and ≤2.0 µA reverse leakage at 8.4 V. It serves as a precision voltage reference or overvoltage clamp in low-power analog signal conditioning and power rail stabilization circuits.

For engineers reviewing the MMBZ5241BW-7 datasheet, MMBZ5241BW-7 pinout, MMBZ5241BW-7 application, or MMBZ5241BW-7 equivalent, key selection criteria include zener voltage accuracy, thermal resistance (625 °C/W), AEC-Q101 qualification, RoHS/Green compliance, and SOT323 footprint compatibility in space-constrained PCB layouts.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain stable voltage regulation across varying load currents up to its 200 mW power limit. Its 22 Ω zener impedance at 20 mA ensures minimal voltage deviation under moderate current changes, while the 625 °C/W junction-to-ambient thermal resistance defines derating behavior above +25°C ambient.

The device uses alloy 42 leadframe with matte tin plating, conforms to J-STD-020D Level 1 moisture sensitivity, and is qualified to AEC-Q101 for automotive-grade reliability - enabling use in engine control modules, body electronics, and infotainment power supervisors where long-term stability and solderability are critical.

Key Specifications

Pinout & Package

Package: SOT323 - ultra-small plastic surface-mount case with gull-wing leads, 0.006 g weight, UL 94V-0 flammability rating, and matte tin-plated terminals solderable per MIL-STD-202.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX384-B11 and MMBZ5241BS-7-F, the MMBZ5241BW-7 offers optimal balance of minimal SOT323 area, AEC-Q101 qualification, and verified 200 mW thermal performance - making it preferred for new automotive and portable designs where board space and qualification rigor are primary constraints.

Availability

MMBZ5241BW-7 is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, medical diagnostic instruments, and consumer IoT power rails requiring stable component supply with full traceability and lifecycle support.

Supply support for MMBZ5241BW-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, specializing in high-reliability components for automotive, industrial, and computing markets with ISO/TS 16949 and ISO 14001 certification.

The MMBZ52xxBW series belongs to Diodes' AEC-Q101-qualified Zener diode product line, engineered specifically for voltage reference and overvoltage protection in harsh-environment electronics where compact size, thermal stability, and regulatory compliance are mandatory.

FAQ

What is the maximum reverse voltage this Zener can withstand before breakdown?

The MMBZ5241BW-7 exhibits sharp reverse breakdown at 10.45–11.55 V when tested at 20 mA. Below 8.4 V, reverse leakage remains ≤2.0 µA - meaning it blocks effectively up to that point. Sustained reverse bias beyond 11.55 V risks exceeding its 200 mW power limit and thermal runaway unless current is externally limited.

Is this part suitable for use in automotive under-hood applications?

Yes - the MMBZ5241BW-7 is fully AEC-Q101 qualified, rated for -65°C to +150°C operating temperature, and built with halogen-free green molding compound. Its SOT323 package passes vibration, thermal shock, and humidity testing per automotive standards, making it appropriate for engine control units and transmission control modules.

How does the SOT323 package affect thermal performance compared to larger packages?

With a junction-to-ambient thermal resistance of 625 °C/W, the SOT323 package dissipates heat less efficiently than TO-236 or SOD-123 variants. At +85°C ambient, its usable power drops to ~100 mW - requiring careful PCB layout (e.g., copper pour under exposed pad, minimal trace length) to avoid exceeding junction temperature limits.

Can this Zener diode replace a 12 V Zener like MMBZ5242BW-7 in the same circuit?

No - the MMBZ5241BW-7 is specified at 11 V (10.45–11.55 V), while MMBZ5242BW-7 is 12 V (11.4–12.6 V). Substituting them alters reference or clamp voltage by ≥0.85 V, potentially causing ADC misreading, regulator instability, or insufficient overvoltage protection. Always verify system-level voltage margins before interchange.