Diodes Incorporated MMBZ5227BW-7-F

Overview

MMBZ5227BW-7-F from Diodes Incorporated is a 3.6 V, 200 mW surface-mount Zener diode in SOT323 package, rated for ±5% zener voltage tolerance at 20 mA test current, with 24 Ω dynamic impedance and ≤15 μA reverse leakage at 1.0 V, used for precision voltage regulation and overvoltage protection in low-power analog sensor interfaces.

For engineers reviewing the MMBZ5227BW-7-F datasheet, MMBZ5227BW-7-F pinout, MMBZ5227BW-7-F application, or MMBZ5227BW-7-F equivalent, key selection criteria include zener voltage accuracy, thermal resistance (625 °C/W), low leakage at bias, SOT323 footprint compatibility, and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown to clamp voltage at its nominal 3.6 V zener point. It exhibits 24 Ω zener impedance at 20 mA and maintains ≤15 μA reverse leakage up to 1.0 V, enabling stable biasing in low-current signal conditioning paths.

Designed for surface-mount assembly on FR4 PCBs with defined pad layout (AP02001), it delivers 200 mW power dissipation at 25°C ambient and derates linearly above 25°C per Fig. 1, with junction-to-ambient thermal resistance of 625 °C/W under standard mounting conditions.

Key Specifications

Pinout & Package

Package: SOT323 - three-terminal plastic case with anode, cathode, and exposed heat sink pad (cathode marked by band); dimensions: 2.10 mm × 1.30 mm × 0.90 mm (L × W × H), weight ≈ 0.006 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C3V6LT1G and MMBZ5227BS-7-F, MMBZ5227BW-7-F offers optimal balance of SOT323 miniaturization, AEC-Q101 qualification, and 24 Ω low-impedance regulation-making it preferred for new automotive and portable medical designs where footprint and reliability are prioritized over raw power headroom.

Availability

MMBZ5227BW-7-F is available at Aetrix Electronics and suitable for industrial sensor signal conditioning, automotive body control module power monitoring, and low-power wearable battery management requiring stable component supply and AEC-Q101-compliant sourcing.

Supply support for MMBZ5227BW-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.

The MMBZ52xxBW series belongs to Diodes' AEC-Q101-qualified Zener diode product line, engineered specifically for voltage regulation, reference, and transient suppression in automotive, industrial, and medical systems where reliability and environmental compliance are critical.

FAQ

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

The MMBZ5227BW-7-F has a nominal zener voltage of 3.6 V with a guaranteed range of 3.42 V to 3.78 V at 20 mA test current. Its reverse breakdown begins within this range; it is not rated for sustained reverse voltage above 3.78 V without entering conduction. The absolute maximum non-repetitive peak reverse voltage is not specified separately-the device is intended for controlled breakdown operation, not blocking.

Is this part suitable for use in high-humidity environments?

Yes. The MMBZ5227BW-7-F uses a "Green" halogen-free molding compound rated UL 94V-0 and is qualified to AEC-Q101, which includes rigorous humidity resistance testing (e.g., biased HAST). Its moisture sensitivity level is Level 1 per J-STD-020D, meaning it can be stored indefinitely at ≤30°C/60% RH without baking prior to assembly.

Does the SOT323 package include a thermal pad, and how should it be handled in PCB layout?

The SOT323 package features an exposed metal pad (Pin 3) that serves solely as a thermal and mechanical anchor-not an electrical terminal. It must be soldered to a dedicated copper pour connected to system ground or thermal plane. Per Diodes' AP02001, the recommended pad layout uses a 1.0 mm × 1.0 mm thermal pad with four 0.3 mm solder dams to prevent floating and ensure void-free reflow.

How does the 200 mW power rating translate to real-world current limits at elevated temperatures?

At 25°C ambient, the device supports up to 55.6 mA at 3.6 V (200 mW / 3.6 V). Above 25°C, power derates linearly at 0.32 mW/°C (1 / 625 °C/W). At 85°C ambient, max dissipation drops to 122 mW, limiting current to ~33.9 mA. This must be verified against actual board thermal performance using Diodes' AP02001 pad layout and FR4 stack-up.