Diodes Incorporated DDZ9688-7

Overview

DDZ9688-7 from Diodes Incorporated is a surface-mount low-current Zener diode with nominal zener voltage 4.7 V (min 4.47 V, max 4.94 V), rated for 500 mW power dissipation on FR-4 PCB at TL = +75°C, specified at low test current of 50 µA, and packaged in SOD123. It serves as a precision voltage reference or overvoltage clamp in portable battery-powered circuits requiring stable low-bias operation.

For engineers reviewing the DDZ9688-7 datasheet, DDZ9688-7 pinout, DDZ9688-7 application, or DDZ9688-7 equivalent, key selection criteria include its 4.7 V zener voltage tolerance, 5 µA maximum reverse leakage at VR = 3 V, SOD123 package thermal resistance (RθJA = 340 °C/W), and suitability for automated assembly in space-constrained consumer and industrial power management designs.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain a stable reference voltage across its terminals under varying load and temperature conditions. Its low 50 µA test current enables minimal quiescent current draw, critical for energy-sensitive applications like coin-cell-powered sensors and wearables.

The device exhibits a typical zener impedance of 150 Ω at IZT = 50 µA and a temperature coefficient of approximately +0.04 %/°C near 4.7 V, indicating moderate positive drift with rising junction temperature - a key design consideration for precision analog references.

Key Specifications

Pinout & Package

Package: SOD123 - Molded plastic case, UL 94V-0 rated, cathode indicated by band marking. Dimensions: L = 0.25–0.40 mm, D = 1.40–1.70 mm, E = 2.55–2.85 mm, weight ≈ 0.01 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C4V7-7-F and MMSZ4704T1G, DDZ9688-7 uniquely supports true low-bias operation (50 µA) without sacrificing 500 mW rating or SOD123 footprint, making it optimal for energy-harvesting and coin-cell applications where standby current dominates lifetime calculation.

Availability

DDZ9688-7 is available at Aetrix Electronics and suitable for portable sensor nodes, USB-C port protection circuits, industrial PLC analog inputs, and medical wearable battery monitoring requiring stable component supply with consistent parametric performance across production lots.

Supply support for DDZ9688-7 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, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

The DDZ9678–DDZ9717 series belongs to Diodes' low-current Zener diode product line, engineered specifically for battery-powered and space-constrained applications demanding minimal bias current, tight voltage tolerance, and robust automated assembly compatibility.

FAQ

What is the maximum reverse voltage (VR) at which DDZ9688-7 guarantees ≤5 µA leakage?

DDZ9688-7 guarantees ≤5 µA reverse leakage current at VR = 3 V, per Electrical Characteristics Table on page 2 of DS30410 Rev. 17-2. This value is measured under standard conditions (TA = +25°C) and defines the upper limit of applied reverse voltage before significant leakage begins - critical for setting clamping thresholds in low-power circuits.

Can DDZ9688-7 be used in place of a 5.1 V Zener for overvoltage protection?

No - DDZ9688-7 has a nominal zener voltage of 4.7 V (range 4.47–4.94 V), not 5.1 V. Substituting it for a 5.1 V part would reduce clamping headroom by ~400 mV, potentially causing premature conduction or inadequate protection margin. Use DDZ9689-7 (5.1 V nominal) instead for that voltage level.

Does DDZ9688-7 require a heatsink for 500 mW operation?

No external heatsink is required, but thermal performance depends entirely on PCB layout. The 500 mW rating assumes mounting on FR-4 with Diodes' recommended SOD123 pad layout (documented in package-outlines.html). Without adequate copper area or thermal vias, actual power handling drops significantly due to RθJA = 340 °C/W.

Is DDZ9688-7 qualified for automotive applications?

No - DDZ9688-7 is the standard-grade part. Automotive-grade equivalents are designated with a "Q" suffix (e.g., DDZ9688Q-7), which are AEC-Q101 qualified, PPAP capable, and manufactured in IATF 16949 certified facilities. Standard DDZ9688-7 lacks those qualifications and is intended for commercial/industrial use only.