Diodes Incorporated SMAZ33-13

Overview

SMAZ33-13 from Diodes Incorporated is a 1.0W surface-mount Zener diode with a nominal zener voltage of 33.0V (±5%), 300Ω maximum zener impedance at 15mA, 0.5µA maximum reverse leakage at 25.1V, and SMA package with cathode band polarity marking. It provides precision voltage regulation in power supply feedback loops, overvoltage protection circuits, and reference voltage generation for industrial sensor interfaces.

For engineers reviewing the SMAZ33-13 datasheet, SMAZ33-13 pinout, SMAZ33-13 application, or SMAZ33-13 equivalent, this page delivers verified electrical parameters, thermal derating behavior, junction-to-ambient thermal resistance, and real-world use context for reliable circuit design and BOM validation.

Technical Context

This Zener diode operates in reverse breakdown mode with a specified test current of 15mA and exhibits a typical differential resistance of ≤300Ω at that bias point. Its 1.0W power rating is derated linearly above +50°C at 10mW/°C when mounted on a standard FR-4 PCB per Diodes Inc.'s recommended pad layout.

The device features a molded plastic SMA case rated UL 94V-0, lead-free matte tin plating compliant with RoHS 2 and halogen/antimony-free "Green" specifications (<900ppm Br, <900ppm Cl, <1000ppm Sb). Polarity is indicated by a visible cathode band on the package body.

Key Specifications

Pinout & Package

SMA (DO-214AC) surface-mount package with two terminals: anode and cathode. Cathode identified by a molded band on the body. No internal leads; terminals are formed from the metallized end caps of the molded plastic case.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C33-7-F and 1N4748A, SMAZ33-13 uniquely balances 1.0W SMT power handling, industry-standard SMA footprint, and low-leakage performance-making it optimal for automated production of mid-power industrial regulators and clamps where thermal management and placement reliability are critical.

Availability

SMAZ33-13 is available at Aetrix Electronics and suitable for industrial power supply feedback, automotive load dump protection, and programmable logic controller I/O protection requiring stable component supply across multi-year production cycles.

Supply support for SMAZ33-13 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 SMAZ series belongs to Diodes' high-reliability Zener diode product line, engineered specifically for surface-mount voltage regulation and transient suppression in industrial, automotive, and medical power systems where consistent parametric stability and RoHS/Green compliance are mandatory.

FAQ

What is the maximum continuous reverse current the SMAZ33-13 can handle without degradation?

The SMAZ33-13 is rated for a maximum zener current (I_ZM) of 15mA at its nominal 33V breakdown, derived from P_D/V_Z = 1.0W/33V ≈ 30mA - but datasheet-specified I_ZM is 15mA due to thermal limits and impedance behavior. Sustained operation above this value risks exceeding junction temperature limits unless PCB copper area and airflow are significantly enhanced beyond the standard FR-4 test board.

Does the SMAZ33-13 meet AEC-Q200 stress testing requirements for automotive use?

No - the SMAZ33-13 is not AEC-Q200 qualified. While it meets RoHS, halogen-free, and JEDEC moisture sensitivity Level 1 standards, Diodes Incorporated does not list it in their AEC-Q200 qualified portfolio. For automotive-grade Zener applications, consider the AZ series (e.g., AZ33-13) which undergoes full temperature cycling, humidity bias, and vibration qualification per AEC-Q200 Rev D.

How does the 300Ω zener impedance affect regulation accuracy under varying load conditions?

At 15mA test current, 300Ω impedance means a 1mA change in zener current causes ~0.3V shift in output voltage. In a feedback divider network drawing 100µA, regulation error remains under ±0.03V; however, in high-current shunt applications (>5mA load variation), additional buffering or tighter tolerance resistors are needed to maintain system accuracy within ±1%.

Can SMAZ33-13 be used in parallel to increase power handling?

No - Zener diodes should not be paralleled due to mismatched breakdown voltages causing current hogging. Even devices from the same reel typically exhibit ±5% V_Z spread, leading to one diode conducting >90% of total current and thermally failing. For higher power, select a single higher-rated device (e.g., 3.0W SMAJ33A) or redesign the clamp topology using active regulation.