Diodes Incorporated MMSZ5235B-7-F

Overview

MMSZ5235B-7-F from Diodes Incorporated is a 6.8 V, 500 mW surface-mount Zener diode in SOD-123 package, rated for 20 mA test current with 5 Ω typical Zener impedance at 20 mA and 3.0 µA maximum reverse leakage at 5.0 V, widely used for voltage regulation and reference in power supply feedback loops and overvoltage protection circuits.

For engineers reviewing the MMSZ5235B-7-F datasheet, MMSZ5235B-7-F pinout, MMSZ5235B-7-F application, or MMSZ5235B-7-F equivalent, key selection criteria include nominal Zener voltage tolerance (±5%), thermal resistance (338 °C/W), AEC-Q101 qualification status, SOD-123 footprint compatibility, and low-leakage performance at sub-breakdown bias.

Technical Context

This Zener diode operates in reverse breakdown to maintain stable voltage across its terminals under varying load and temperature conditions. Its 6.8 V nominal Zener voltage is specified at 20 mA test current, with ±5% tolerance (6.46–7.14 V) and a temperature coefficient of +0.055 %/°C, enabling predictable drift compensation in precision references.

The device uses a silicon planar junction structure with cathode band polarity marking, optimized for automated pick-and-place assembly. It delivers 500 mW power dissipation at lead temperature of 75 °C and 370 mW at ambient 25 °C on FR-4 PCB with 1-inch copper pad, supporting reliable operation in compact industrial and automotive power rails.

Key Specifications

Pinout & Package

Package: SOD-123 - surface-mount plastic case with cathode band marking, 1.00–1.35 mm height, 2.55–2.85 mm width, and 3.55–3.85 mm length; compatible with IPC-7351B SOIC-123 footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX584C6V8 and 1N4735A, MMSZ5235B-7-F offers optimal balance of SMD manufacturability, 500 mW power capability, and low 5 Ω impedance-making it preferred for production-grade automotive and industrial SMPS feedback networks requiring AEC-Q101 compliance.

Availability

MMSZ5235B-7-F is available at Aetrix Electronics and suitable for switch-mode power supplies, microcontroller reference circuits, I/O protection clamps, and automotive body control modules requiring stable component supply and AEC-Q101 assurance.

Supply support for MMSZ5235B-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 Dallas, Texas, with design, manufacturing, and sales operations across Asia, Europe, and the Americas.

The MMSZ52xxB series belongs to Diodes' general-purpose Zener diode product line, engineered for cost-effective, high-reliability voltage regulation in commercial and automotive power management systems.

FAQ

What is the maximum reverse voltage that can be applied before breakdown?

The MMSZ5235B-7-F exhibits sharp Zener breakdown at 6.46–7.14 V when reverse biased at 20 mA. Below this range, reverse leakage remains ≤3.0 µA up to 5.0 V. Applying >7.14 V continuously without current limiting risks thermal runaway due to uncontrolled power dissipation beyond 370 mW.

Is MMSZ5235B-7-F suitable for use in automotive applications?

Yes-MMSZ5235B-7-F is explicitly qualified to AEC-Q101 standards, including stress tests for temperature cycling, high-temperature reverse bias, and electrostatic discharge. Its −65 °C to +150 °C operating range and green, halogen-free construction meet automotive Tier-1 supplier requirements for body electronics and infotainment subsystems.

How does the SOD-123 package affect thermal performance?

The SOD-123 package has a junction-to-ambient thermal resistance of 338 °C/W on standard FR-4 with 1-inch copper pad. This limits continuous power to 370 mW at 25 °C ambient. For higher power, thermal vias or larger copper areas are required-unlike TO-220 or SOT-223 packages, SOD-123 relies heavily on PCB layout for heat dissipation.

Can MMSZ5235B-7-F replace MMSZ5234B-7-F in existing designs?

Only if the circuit tolerates a 0.6 V increase in Zener voltage-from 6.2 V (MMSZ5234B) to 6.8 V (MMSZ5235B). Both share identical SOD-123 package, 20 mA test current, and 5 Ω Z_ZT, but the higher voltage shifts regulation points and may cause overvoltage in feedback paths calibrated for 6.2 V.