Diodes Incorporated DDZ9705T-7

Overview

DDZ9705T-7 from Diodes Incorporated is a surface-mount Zener diode with nominal zener voltage 18 V, ±5% tolerance (17.1–18.9 V), 150 mW power dissipation, 0.05 µA reverse leakage at 13.6 V, and SOD523 package. It provides precise voltage regulation in low-power biasing, reference, and overvoltage protection circuits for portable electronics and sensor signal conditioning.

For engineers reviewing the DDZ9705T-7 datasheet, DDZ9705T-7 pinout, DDZ9705T-7 application, or DDZ9705T-7 equivalent, key selection criteria include zener voltage accuracy, low leakage at rated VR, thermal resistance (833 °C/W), sharp breakdown characteristics, and compatibility with automated SMT assembly on FR-4 PCBs.

Technical Context

This Zener diode operates in reverse-bias breakdown mode to maintain stable voltage across its terminals under varying current loads (IZT = 50 µA). Its sharp knee and low dynamic impedance ensure minimal voltage deviation during transient load changes.

Designed for thermal equilibrium at 30°C, it exhibits a temperature coefficient of approximately +0.07 %/°C near 18 V (per Fig. 17), enabling predictable drift compensation in precision references. The SOD523 package supports high-density layouts while limiting self-heating via controlled junction-to-ambient thermal resistance.

Key Specifications

Pinout & Package

Two-terminal device in SOD523 package: cathode marked by band; anode unmarked. Molded plastic case meets UL 94V-0; terminals are matte tin annealed over Alloy 42 leadframe, solderable per MIL-STD-202.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX584-C18 and MMSZ4689, DDZ9705T-7 offers optimal balance of ultra-small SOD523 footprint, industry-leading low leakage (0.05 µA), and RoHS/halogen-free compliance-making it preferred for miniaturized, battery-critical, and green-design applications.

Availability

DDZ9705T-7 is available at Aetrix Electronics and suitable for portable power management, sensor signal conditioning, low-power microcontroller biasing, and industrial control loop reference applications requiring stable component supply and full RoHS compliance.

Supply support for DDZ9705T-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 and manufacturing operations across Asia and the Americas.

This device belongs to the DDZ9689T–DDZ9717T Zener diode family, engineered specifically for high-accuracy, low-leakage voltage regulation in space-constrained, energy-sensitive applications such as wearables, IoT edge nodes, and portable instrumentation.

FAQ

What is the maximum reverse voltage (VR) at which DDZ9705T-7 guarantees ≤0.05 µA leakage?

DDZ9705T-7 guarantees ≤0.05 µA reverse leakage current at VR = 13.6 V, as specified in the Electrical Characteristics table. This value is measured under standard test conditions (TA = +25°C) using short-duration pulses to minimize self-heating effects. Operation above 13.6 V increases leakage exponentially and may trigger breakdown.

Can DDZ9705T-7 be used in place of a 15 V Zener diode like DDZ9702T?

No-DDZ9705T-7 is a dedicated 18 V Zener diode with a nominal voltage of 18 V (range 17.1–18.9 V); substituting it for a 15 V part (DDZ9702T: 14.25–15.75 V) would cause incorrect biasing or overvoltage in circuits relying on precise 15 V regulation. Voltage-specific Zeners are not interchangeable without redesigning the surrounding bias network.

Does DDZ9705T-7 have a specified zener impedance (ZZT)?

Yes-Figure 12 in the datasheet shows typical zener impedance for DDZ9699T–DDZ9705T devices. At IZT = 50 µA and TA = +25°C, DDZ9705T-7 exhibits ~350 Ω dynamic impedance. This value decreases with increasing test current and is critical for evaluating regulation stability under varying load conditions.

Is the SOD523 package of DDZ9705T-7 compatible with standard reflow profiles for lead-free soldering?

Yes-the SOD523 package uses matte tin annealed terminals qualified per MIL-STD-202, Method 208, and is rated for moisture sensitivity Level 1 per J-STD-020D. It supports standard lead-free reflow profiles (peak 260°C, 60–90 sec above 217°C) when mounted on FR-4 with the recommended pad layout from Diodes Incorporated's package outline documentation.