Diodes Incorporated MMBZ5229BW-7-F

Overview

MMBZ5229BW-7-F from Diodes Incorporated is a 4.3 V, 200 mW surface-mount Zener diode in SOT323 package, with ±5% tolerance (4.09–4.52 V), 22 Ω dynamic impedance at 20 mA, and 5.0 μA reverse leakage at 1.0 V. It provides precision voltage regulation in low-power signal conditioning and power rail clamping circuits.

For engineers reviewing the MMBZ5229BW-7-F datasheet, MMBZ5229BW-7-F pinout, MMBZ5229BW-7-F application, or MMBZ5229BW-7-F equivalent, key selection criteria include nominal Zener voltage accuracy, low leakage at sub-breakdown bias, thermal resistance (625 °C/W), 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 maintain stable voltage across its terminals under controlled current. Its 200 mW power rating and 625 °C/W junction-to-ambient thermal resistance define safe operating limits on standard FR4 PCBs with recommended pad layout.

The Zener exhibits 22 Ω impedance at 20 mA test current and 2000 Ω at 0.25 mA knee current, supporting both regulated biasing and transient overvoltage clamping. Its 5.0 μA leakage at VR = 1.0 V enables low-quiescent-current sensing and reference applications.

Key Specifications

Pinout & Package

Package: SOT323 - 3-pin, 2-terminal surface-mount plastic case (0.006 g weight), UL 94V-0 rated, moisture sensitivity Level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C4V3-7-F and MMBZ5229BS-7-F, MMBZ5229BW-7-F offers optimal balance of compact SOT323 size, AEC-Q101 qualification, and precise 4.3 V regulation-making it preferred for automotive and space-constrained industrial designs where single-device simplicity and reliability are critical.

Availability

MMBZ5229BW-7-F is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial I/O protection, and low-power reference voltage generation requiring stable component supply and long-term lifecycle support.

Supply support for MMBZ5229BW-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 consumer markets.

The MMBZ52xxBW series belongs to Diodes' precision Zener diode product line, engineered for stable voltage regulation and transient suppression in space-constrained, high-reliability applications.

FAQ

What is the maximum continuous Zener current for MMBZ5229BW-7-F at +70°C ambient?

At +70°C ambient, the 200 mW power rating derates to 150 mW (per Fig. 1), allowing a maximum continuous Zener current of approximately 34.9 mA (150 mW ÷ 4.3 V). This assumes proper PCB copper area per AP02001 layout guidelines to maintain thermal resistance near 625 °C/W.

Is MMBZ5229BW-7-F suitable for bidirectional ESD protection?

No - MMBZ5229BW-7-F is a unidirectional Zener diode optimized for reverse-bias regulation. For bidirectional ESD protection, TVS diodes such as D3V3M1U2S-7-F (3.3 V, 15 kV contact ESD) are specifically designed with symmetrical clamping and faster response.

How does the 5.0 μA reverse leakage at 1.0 V impact high-impedance voltage divider networks?

At 1.0 V reverse bias, 5.0 μA leakage introduces ≤5 kΩ parallel resistance into the network. In dividers with total resistance >100 kΩ, this adds <5% error - acceptable for non-precision monitoring but insufficient for <0.1% reference accuracy, where lower-leakage alternatives like BZX84-B4V3 (1.0 μA) should be considered.

Can MMBZ5229BW-7-F replace MMBZ5230BW-7-F in a 4.7 V circuit?

No - MMBZ5229BW-7-F has a nominal Zener voltage of 4.3 V (4.09–4.52 V), while MMBZ5230BW-7-F is rated at 4.7 V (4.47–4.94 V). Substituting them would shift regulation by ~0.4 V, potentially causing undervoltage lockout or incorrect comparator triggering; voltage-specific selection is mandatory.