Diodes Incorporated MMBZ5248B-7-F

Overview

MMBZ5248B-7-F from Diodes Incorporated is a 18 V, 350 mW surface-mount Zener diode in SOT23 package, rated for 7.0 mA test current with 21 Ω dynamic impedance at 1 kHz and 0.1 µA reverse leakage at 14 V. It provides precision voltage regulation in low-power analog rails and I/O protection circuits on FR-4 PCBs.

For engineers reviewing the MMBZ5248B-7-F datasheet, MMBZ5248B-7-F pinout, MMBZ5248B-7-F application, or MMBZ5248B-7-F equivalent, this page delivers verified electrical parameters, thermal derating behavior, JEDEC-compliant reliability data, and direct SOT23 terminal mapping - all critical for ESD clamp design, reference voltage stabilization, and overvoltage threshold setting.

Technical Context

This Zener diode operates in reverse breakdown mode with tightly controlled nominal voltage (17.1–18.9 V), specified at 7.0 mA test current (IZT) and validated under JEDEC high-reliability standards. Its 21 Ω Zener impedance (ZZT) at 1 kHz ensures stable regulation under small-signal AC load variations.

Thermal performance is defined for FR-4 mounting: 357 °C/W junction-to-ambient resistance enables 350 mW dissipation at 25 °C ambient, with linear derating above 25 °C per Figure 1. Reverse leakage remains ≤0.1 µA up to 14 V (VR), supporting low-quiescent-current bias networks.

Key Specifications

Pinout & Package

Package: SOT23 - 3-terminal surface-mount plastic package with matte tin-plated Alloy 42 leadframe, UL 94V-0 rated, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C18LT1G, MMBZ5248B-7-F offers 30% lower Zener impedance and 17% higher power rating - critical for precision references and repetitive transient suppression. Versus MMBZ5248BS-7-F, it shares identical performance but differs only in internal die attach flag routing, with no impact on circuit function or layout.

Availability

MMBZ5248B-7-F is available at Aetrix Electronics and suitable for IO protection clamp, voltage reference source, and low-power supply rail clamp applications requiring stable component supply, consistent parametric performance, and long-term manufacturing continuity.

Supply support for MMBZ5248B-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 industrial, computing, and automotive markets.

This device belongs to the MMBZ52xxB series of 350 mW Zener diodes designed for precision voltage regulation and transient suppression in space-constrained, high-volume surface-mount applications.

FAQ

What is the maximum reverse voltage (VR) at which MMBZ5248B-7-F guarantees ≤0.1 µA leakage?

The datasheet specifies ≤0.1 µA reverse leakage current at VR = 14 V. This value is measured under steady-state DC conditions at 25 °C ambient and defines the upper limit of applied reverse voltage before significant leakage begins - critical for low-power bias networks and high-impedance sensing nodes.

Can MMBZ5248B-7-F be used in place of a 15 V Zener like MMBZ5245B-7-F for overvoltage protection?

No - its 17.1–18.9 V Zener range is incompatible with 15 V system thresholds. Substituting it would raise the clamping voltage by ≥2.1 V, risking damage to downstream 15 V-rated components during transients. Always match nominal Zener voltage to the protected rail's absolute maximum rating.

Does the "-7-F" suffix indicate tape-and-reel packaging and lead-free finish?

Yes - "-7-F" denotes 3,000-unit tape-and-reel packaging with fully RoHS-compliant, lead-free plating (matte tin over Alloy 42). The "F" confirms compliance with EU Directive 2015/863/EU, including halogen- and antimony-free "Green" compound requirements.

How does thermal derating affect MMBZ5248B-7-F's usable power at 70 °C ambient?

Per Figure 1, power dissipation linearly derates from 350 mW at 25 °C to zero at 150 °C. At 70 °C ambient, usable power is 350 mW × (1 − (70−25)/125) = 245 mW. This must be respected in sustained-clamp scenarios to avoid thermal runaway or parameter shift.