Diodes Incorporated SMAZ39-13

Overview

SMAZ39-13 from Diodes Incorporated is a 1.0W surface-mount Zener diode with a nominal zener voltage of 39.0V (±5% tolerance), 10mA test current, 40Ω maximum zener impedance at 10mA, and 0.5µA maximum reverse leakage at 29.6V. It features SMA package, RoHS-compliant matte tin plating, and is used for voltage regulation and overvoltage protection in DC power rails.

For engineers reviewing the SMAZ39-13 datasheet, SMAZ39-13 pinout, SMAZ39-13 application, or SMAZ39-13 equivalent, key selection criteria include zener voltage accuracy, power derating above +50°C, thermal resistance (RθJA = 100°C/W), and compatibility with automated SMT assembly on FR-4 PCBs.

Technical Context

This Zener diode operates in reverse breakdown to maintain stable reference voltage under varying load and line conditions. Its 39.0V nominal regulation supports mid-to-high-voltage rail clamping and feedback sensing in switch-mode power supplies and industrial control circuits.

Designed for surface-mount reliability, it delivers 1.0W power dissipation at +25°C, derating linearly at 10mW/°C above +50°C. The SMA package provides low thermal resistance (RθJT = 30°C/W) and meets J-STD-020 Level 1 moisture sensitivity.

Key Specifications

Pinout & Package

The SMA package is a 2-terminal surface-mount device with cathode identified by a band or notch. No internal pin numbering applies - terminals are anode and cathode only.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C39 and 1N4763A, SMAZ39-13 uniquely balances 1.0W SMT power handling, industry-standard SMA footprint, and 100°C/W thermal performance on FR-4 - making it optimal for modern high-density, automated power supply designs where both regulation accuracy and assembly efficiency matter.

Availability

SMAZ39-13 is available at Aetrix Electronics and suitable for industrial power supply protection, automotive ECU voltage reference, and telecom DC-DC feedback networks requiring stable component supply and full RoHS/halogen-free compliance.

Supply support for SMAZ39-13 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 and manufacturing operations across Asia and the Americas.

The SMAZ series belongs to Diodes' general-purpose Zener diode product line, engineered specifically for reliable voltage regulation and transient suppression in high-volume industrial, automotive, and communications power systems.

FAQ

What is the maximum continuous reverse voltage (V_RWM) for SMAZ39-13?

The SMAZ39-13 does not specify a distinct V_RWM; its rated zener voltage (39.0V) defines the nominal regulation point. Per datasheet, reverse leakage remains ≤0.5µA at 29.6V - meaning it begins conducting significantly only near 37V. For clamping applications, use 40.95V (V_Z max) as the practical upper limit before excessive power dissipation occurs.

Can SMAZ39-13 be used in parallel for higher power handling?

No - Zener diodes exhibit negative temperature coefficients and mismatched V_Z tolerances, causing current hogging when paralleled. Even with matched units, thermal runaway risk remains high. For >1.0W regulation, use a single higher-rated Zener (e.g., 5W axial) or active regulation with a transistor and reference IC instead.

Is the SMAZ39-13 suitable for surge protection per IEC 61000-4-5?

No - SMAZ39-13 is a precision Zener diode, not a transient voltage suppressor (TVS). Its 1.0W rating and 40Ω impedance are insufficient for line-surge energy absorption. For IEC 61000-4-5 compliance, use dedicated TVS diodes like SMBJ36A (36V, 600W peak) with defined clamping voltage and response time.

What is the recommended solder profile for SMAZ39-13?

Per J-STD-020 Level 1 classification, SMAZ39-13 supports standard lead-free reflow profiles: peak temperature ≤260°C, time above 217°C ≤60 seconds, ramp-up rate ≤3°C/sec. No prebake is required. Use standard SnAgCu paste and verify thermal relief pad design per Diodes' SMA outline (document DS18015, page 4).