Diodes Incorporated DDZ43Q-7

Overview

DDZ43Q-7 from Diodes Incorporated is a surface-mount precision Zener diode with nominal zener voltage 42.14–43.86 V at 5 mA test current, ±2.5% tolerance, 90 Ω dynamic impedance at 5 mA, and 0.05 µA reverse leakage at 33 V. It operates in SOD123 package, rated for 294 mW power dissipation on minimal PCB pad layout, and is AEC-Q101 qualified for automotive voltage reference and overvoltage protection circuits.

For engineers reviewing the DDZ43Q-7 datasheet, DDZ43Q-7 pinout, DDZ43Q-7 application, or DDZ43Q-7 equivalent, this part serves as a stable, low-leakage, temperature-stable voltage reference in power supply feedback loops, battery monitoring, and ECU sensor biasing - where tight V_Z tolerance and automotive-grade reliability are required.

Technical Context

This Zener diode functions as a two-terminal shunt voltage regulator, maintaining a stable reference voltage across its cathode-anode terminals when reverse-biased above its breakdown threshold. Its 43 V nominal rating places it in the high-voltage Zener range, where temperature coefficient rises to +0.09%/°C (typical), and dynamic impedance increases to 90 Ω due to lower doping efficiency at higher voltages.

The device uses planar epitaxial construction with controlled diffusion to achieve tight V_Z distribution and low noise performance. Its SOD123 package enables automated placement while limiting thermal resistance to 425 °C/W under minimal copper pad conditions - critical for thermal stability in compact automotive modules.

Key Specifications

Pinout & Package

DDZ43Q-7 is a two-terminal SOD123 packaged Zener diode. The cathode is marked by a visible band on the body; the anode is unmarked. No internal circuitry or control logic exists - operation depends solely on reverse-bias junction behavior.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C43LT1G and MMSZ43ET1G, DDZ43Q-7 delivers tighter voltage tolerance and lower leakage in the same SOD123 footprint, making it optimal for ASIL-B–level voltage sensing where accuracy and quiescent current directly impact functional safety metrics.

Availability

DDZ43Q-7 is available at Aetrix Electronics and suitable for automotive battery management, 48 V power conversion, and ECU sensor biasing requiring stable component supply, full traceability, and long-term lifecycle assurance.

Supply support for DDZ43Q-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 DDZ series targets precision voltage reference needs in automotive electronics, designed specifically to meet AEC-Q101 stress requirements and deliver tight Zener tolerance in miniature SOD123 packaging.

FAQ

What is the maximum continuous reverse voltage that DDZ43Q-7 can withstand without breakdown?

DDZ43Q-7 begins regulating at its nominal zener voltage range of 42.14–43.86 V when reverse-biased at 5 mA. Below this threshold - specifically at VR = 33 V - reverse leakage remains ≤0.05 µA. It is not rated for continuous operation below breakdown; sustained voltage below V_Z results in only leakage current, not regulation.

Does DDZ43Q-7 require a series current-limiting resistor in all applications?

Yes - as a shunt regulator, DDZ43Q-7 must be used with a series resistor to limit current through the diode and prevent thermal runaway. For example, at 48 V input and 43 V output, a 1 kΩ resistor limits worst-case current to ~5 mA, aligning with its test condition and ensuring safe 294 mW dissipation on minimal PCB copper.

How does the SOD123 package affect thermal performance compared to larger packages like DO-35?

The SOD123 package has higher thermal resistance (425 °C/W vs. ~200 °C/W for DO-35) due to smaller silicon die area and limited copper pad contact. This reduces maximum sustainable power at elevated ambient temperatures - e.g., derating begins at ~75°C ambient instead of ~100°C for DO-35 - requiring careful thermal layout in enclosed automotive modules.

Is DDZ43Q-7 suitable for use in high-frequency noise suppression applications?

No - DDZ43Q-7 is optimized for DC and low-frequency voltage reference, not RF clamping. Its typical capacitance is ~1.5 pF at 2 V reverse bias (per Fig. 10 extrapolation), too low for effective high-frequency filtering; dedicated TVS diodes with sub-nanosecond response and defined clamping curves are required for ESD or fast transient suppression.