Diodes Incorporated DDZ33Q-7

Overview

DDZ33Q-7 from Diodes Incorporated is a precision surface-mount Zener diode designed for voltage regulation and reference applications in power supply feedback loops, analog signal conditioning, and overvoltage protection circuits. It delivers a nominal Zener voltage of 33 V with ±4.5% tolerance (32.14–33.79 V at I_ZT = 5 mA), 75 Ω maximum Zener impedance at test current, and 0.05 µA maximum reverse leakage at 27 V. Its SOD123 package supports automated assembly and meets AEC-Q101 for automotive-grade reliability.

For engineers reviewing the DDZ33Q-7 datasheet, DDZ33Q-7 pinout, DDZ33Q-7 application, or DDZ33Q-7 equivalent, key selection criteria include Zener voltage accuracy at low test current (5 mA), thermal resistance (425 °C/W on minimal pad layout), temperature coefficient (~0.08 %/°C per Fig. 19), and compliance with AEC-Q101, RoHS, and halogen-free requirements.

Technical Context

This device operates as a two-terminal shunt regulator, maintaining stable output voltage across varying load and line conditions by conducting reverse current above its breakdown threshold. Its low 5 mA test current enables efficient biasing in low-power reference designs, while tight V_Z tolerance ensures predictable trip points in protection circuits.

The SOD123 package features a cathode band marking, matte tin–annealed Alloy 42 leadframe, and UL 94V-0 molding compound. Thermal performance is specified under two mounting conditions: 425 °C/W (minimal pad) and 266 °C/W (1 in² copper pad), directly impacting power derating in compact PCB layouts.

Key Specifications

Pinout & Package

DDZ33Q-7 uses the SOD123 surface-mount package with two terminals: anode and cathode. The cathode is marked by a visible band on the device body. No internal die bonding or multi-pin functionality is present - it is a passive two-terminal device.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C33LT1G and MMSZ5260BT1G, DDZ33Q-7 offers superior voltage accuracy (±4.5% vs. ±5%), lower dynamic impedance (75 Ω vs. ≥90 Ω), and full AEC-Q101/PPAP support - making it the only choice for automotive power management and medical-grade clamping where long-term parametric stability is mandatory.

Availability

DDZ33Q-7 is available at Aetrix Electronics and suitable for automotive power monitoring, industrial sensor excitation, PLC input protection, and medical device voltage clamping requiring stable component supply across extended product lifecycles.

Supply support for DDZ33Q-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 and protection applications in harsh environments, with design emphasis on tight V_Z tolerance, low leakage, and AEC-Q101 qualification for under-hood and safety-critical systems.

FAQ

What is the maximum power dissipation of DDZ33Q-7 at 75°C ambient?

At T_L = +75°C, DDZ33Q-7 supports 500 mW power dissipation per the datasheet's Note 6. This rating applies when mounted on a thermally enhanced land pattern (e.g., large copper pour), enabling higher continuous operation than the 294 mW rating on minimal pads at 25°C ambient.

How does the temperature coefficient affect regulation accuracy over −40°C to +125°C?

Per Figure 19, DDZ33Q-7 exhibits ~0.08 %/°C TC near 33 V. Over a 165°C span, this yields ≈13.2 mV/°C × 165°C = ±2.18 V total drift, or ±6.6% of nominal V_Z. System-level compensation or calibration is recommended for sub-1% total error budgets.

Is DDZ33Q-7 compatible with lead-free reflow profiles?

Yes - DDZ33Q-7 is fully RoHS 3 compliant and rated for standard JEDEC J-STD-020 lead-free reflow profiles (peak 260°C). Its matte tin–annealed leadframe ensures reliable wetting and intermetallic formation without voiding or dewetting.

What is the significance of the 'Q' suffix in DDZ33Q-7?

The 'Q' denotes AEC-Q101 qualification and PPAP capability. It confirms the part was manufactured in IATF 16949-certified facilities, with controlled change management, lot traceability, and automotive-specific reliability testing - distinguishing it from commercial-grade DDZ33-7.