Diodes Incorporated DDZ9685Q-7

Overview

DDZ9685Q-7 from Diodes Incorporated is a surface-mount, low-current Zener diode in SOD123 package, rated for 3.6 V nominal zener voltage (3.42–3.78 V), 50 µA test current, and 500 mW power dissipation at TL = +75°C on FR-4 PCB. It features AEC-Q101 qualification, automotive PPAP capability, and is optimized for precision voltage reference in battery-powered sensor nodes and low-bias analog monitoring circuits.

For engineers reviewing the DDZ9685Q-7 datasheet, DDZ9685Q-7 pinout, DDZ9685Q-7 application, or DDZ9685Q-7 equivalent, this part serves as a stable, low-leakage (7.5 µA @ 2 V reverse) automotive-grade voltage clamp and reference in space-constrained, thermally sensitive designs requiring IATF 16949 traceability and halogen/antimony-free "Green" compliance.

Technical Context

This Zener diode operates in reverse breakdown mode with tightly controlled zener voltage tolerance (±5% at 3.6 V) and low dynamic impedance-typical zener impedance is <30 Ω at IZ = 5 mA per Figure 11. Its thermal coefficient is +0.03 %/°C near 3.6 V (Fig. 17), enabling predictable drift in ambient temperature ranges from –65°C to +150°C.

The device uses a planar epitaxial construction with cathode band marking, matte tin–annealed Alloy 42 leadframe, and UL 94V-0 molded plastic case. It delivers stable regulation under low bias conditions (50 µA test current), making it suitable for ultra-low-power wake-up circuits and precision ADC reference stabilization where self-heating must be minimized.

Key Specifications

Pinout & Package

Package: SOD123 - surface-mount, single-ended, cathode-band-marked plastic case (1.05 mm height × 2.65 mm width × 3.65 mm length); moisture sensitivity level 1 per J-STD-020; weight ≈ 0.01 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C3V6-7-F and MMSZ4685T1G, DDZ9685Q-7 uniquely combines automotive qualification, tighter thermal performance (RθJL = 150 °C/W), and guaranteed low-leakage behavior at 2 V reverse bias-making it the sole choice for safety-critical, thermally constrained, and production-validated designs.

Availability

DDZ9685Q-7 is available at Aetrix Electronics and suitable for automotive cabin electronics, industrial 4–20 mA transmitters, portable medical sensors, and smart utility metering requiring stable component supply with full AEC-Q101 documentation and traceable sourcing.

Supply support for DDZ9685Q-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 DDZ96xxQ series belongs to Diodes' automotive-qualified Zener diode product line, engineered specifically for robust voltage reference and clamping in harsh-environment electronic control units where reliability, low leakage, and regulatory compliance are mandatory.

FAQ

What is the maximum reverse voltage (VR) at which DDZ9685Q-7 guarantees ≤7.5 µA leakage?

DDZ9685Q-7 guarantees ≤7.5 µA reverse leakage current at VR = 2 V, as specified in the Electrical Characteristics table (Note 7). This value is measured using short-duration pulse testing to minimize self-heating effects, ensuring accurate low-bias characterization for battery-sensitive applications.

Can DDZ9685Q-7 be used in place of a 3.3 V Zener diode for 3.3 V rail clamping?

No-DDZ9685Q-7 has a nominal zener voltage of 3.6 V (min 3.42 V, max 3.78 V), making it unsuitable as a direct replacement for a 3.3 V Zener. Using it for 3.3 V rail clamping would result in insufficient margin against overvoltage and potential failure to activate during transients below 3.42 V.

Is the SOD123 package of DDZ9685Q-7 compatible with IPC-7351B standard land patterns?

Yes-the SOD123 outline dimensions (A = 1.05 mm, D = 1.55 mm, E = 2.65 mm, L = 0.30 mm) align with IPC-7351B Level B recommendations. Diodes Incorporated provides a verified SOD123 pad layout on its package-outlines webpage, supporting reliable solder joint formation and automated optical inspection.

Does DDZ9685Q-7 require derating when mounted on 1 oz copper versus 2 oz copper PCB?

Yes-thermal derating depends on PCB copper weight and pad area. The datasheet specifies 500 mW at TL = +75°C using minimum recommended FR-4 pad layout (1-inch² copper). With 2 oz copper and extended thermal pads, power handling improves; with 1 oz copper and minimal pads, RθJA increases beyond 340 °C/W, requiring stricter derating per Figure 1.