Diodes Incorporated DDZ9678Q-7

Overview

DDZ9678Q-7 from Diodes Incorporated is a surface-mount, low-current Zener diode in SOD123 package, rated for 1.8 V nominal zener voltage (±5% tolerance), 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 and overvoltage protection in battery-powered sensor nodes and low-power MCU reset circuits.

For engineers reviewing the DDZ9678Q-7 datasheet, DDZ9678Q-7 pinout, DDZ9678Q-7 application, or DDZ9678Q-7 equivalent, this part delivers stable low-current zener regulation with tight voltage tolerance, ultra-low leakage (<7.5 µA @ VR = 1 V), and IATF 16949-certified manufacturing - critical for automotive body electronics, portable medical monitors, and industrial IoT edge sensors requiring long-term bias stability.

Technical Context

This Zener diode operates in reverse breakdown mode with a nominal zener voltage of 1.8 V, specified at IZT = 50 µA to ensure minimal quiescent current draw. Its thermal resistance junction-to-lead is 150 °C/W, enabling reliable operation up to +150°C junction temperature under controlled PCB layout conditions.

The device exhibits a negative temperature coefficient (~−0.06 %/°C at 1.8 V) and typical zener impedance of ~100 Ω at 1 mA, supporting stable reference performance across ambient temperatures from −65°C to +150°C. Its SOD123 package supports automated pick-and-place assembly and meets J-STD-020 Level 1 moisture sensitivity requirements.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C1V8LT1G and MMSZ4678T1G, DDZ9678Q-7 uniquely combines AEC-Q101 qualification, 50 µA test current, and 340 °C/W RθJA - enabling direct replacement in safety-critical automotive modules without thermal redesign or process requalification.

Availability

DDZ9678Q-7 is available at Aetrix Electronics and suitable for automotive body electronics, portable medical devices, industrial PLC inputs, and smart home sensor systems requiring stable component supply with full automotive traceability and lifecycle management.

Supply support for DDZ9678Q-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, specializing in high-reliability components for automotive, industrial, and computing markets.

The DDZ9678Q-7 belongs to Diodes' AEC-Q101-qualified Zener diode family, engineered specifically for low-power voltage reference and transient suppression in harsh-environment automotive subsystems.

FAQ

What is the maximum reverse voltage (VR) at which DDZ9678Q-7 guarantees ≤7.5 µA leakage?

DDZ9678Q-7 guarantees maximum reverse leakage current of 7.5 µA at VR = 1 V, as specified in the Electrical Characteristics table. This value is measured under standard test conditions (TA = +25°C) using short-duration pulse testing to minimize self-heating effects. The leakage increases exponentially beyond this voltage, reaching ~100 µA at VR = 1.5 V per typical curves in Figure 21.

Can DDZ9678Q-7 be used in place of a 2.0 V Zener diode in a 3.3 V LDO feedback network?

No - DDZ9678Q-7 has a nominal zener voltage of 1.8 V (range 1.71–1.89 V), not 2.0 V. Substituting it would shift the regulated output voltage downward by ~200 mV, potentially violating downstream logic voltage thresholds. For 2.0 V reference, consider DDZ9681Q-7 (2.4 V) or MMBZ5222BS (2.0 V, commercial grade), but verify tolerance stack-up and thermal drift.

Does DDZ9678Q-7 require heatsinking on standard FR-4 PCB?

No additional heatsinking is required for continuous operation at ≤500 mW dissipation, provided the PCB uses Diodes Incorporated's recommended SOD123 pad layout (1-inch² copper area, minimum trace width). Derating begins linearly above +75°C board temperature, reaching zero power at +150°C ambient per Figure 1. Thermal performance degrades significantly with undersized pads or no thermal relief.

Is the SOD123 package of DDZ9678Q-7 compatible with IPC-7351B footprint standards?

Yes - the SOD123 outline dimensions (D = 1.55 mm typ, E = 2.65 mm typ, L = 0.30 mm typ) align with IPC-7351B "SOD-123" generic footprint. Diodes' recommended pad layout (available at diodes.com/package-outlines.html) specifies 0.6 mm pad width and 2.0 mm pad length, matching IPC Class L tolerances for automated assembly yield >99.98% at 0402-equivalent placement accuracy.