Diodes Incorporated BZX84C3V9Q-13-F

Overview

BZX84C3V9Q-13-F from Diodes Incorporated is a 3.9 V, 5 mA nominal Zener diode in SOT23 package, rated for 350 mW power dissipation, with 90 Ω maximum Zener impedance at test current and ±3.5 mV/°C temperature coefficient. It serves as a precision voltage reference or overvoltage clamp in low-power analog signal conditioning and power rail stabilization circuits.

For engineers reviewing the BZX84C3V9Q-13-F datasheet, BZX84C3V9Q-13-F pinout, BZX84C3V9Q-13-F application, or BZX84C3V9Q-13-F equivalent, key selection criteria include Zener voltage tolerance (±0.2 V), low reverse leakage (≤3.0 µA at 1.0 V), automotive-grade AEC-Q101 qualification, and SOT23-compatible footprint for high-density PCB layouts.

Technical Context

This Zener diode operates in reverse breakdown mode with a nominal regulation voltage of 3.9 V at 5.0 mA test current. Its planar die construction ensures stable voltage regulation across temperature, supported by a defined temperature coefficient of –3.5 mV/°C and thermal resistance of 357 °C/W under ambient-sink conditions.

The device is optimized for surface-mount automated assembly and meets AEC-Q101 stress testing requirements for automotive electronics. Its 350 mW power rating applies when terminals are maintained at ambient temperature, and its 90 Ω dynamic impedance at I_ZT enables predictable regulation under moderate load transients.

Key Specifications

Pinout & Package

Package: SOT23 - three-terminal surface-mount plastic package with matte tin-plated alloy 42 leadframe, UL 94V-0 rated molding compound, and moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMSZ4V3T1G and BZX84-C3V9,115, the BZX84C3V9Q-13-F uniquely combines automotive qualification, 10,000-piece reel packaging for high-volume SMT lines, and SOT23 footprint compatibility-making it optimal for Tier-1 automotive electronics requiring traceable, high-reliability Zener references.

Availability

BZX84C3V9Q-13-F is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor interfaces, USB-C power monitors, and low-power IoT voltage supervisors requiring stable component supply across extended temperature ranges and high-reliability manufacturing environments.

Supply support for BZX84C3V9Q-13-F 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 BZX84 series belongs to Diodes' standard Zener diode product line, engineered specifically for precision voltage regulation and overvoltage protection in cost-sensitive, high-volume applications including automotive electronics and industrial controls.

FAQ

What is the maximum reverse voltage (V_R) that BZX84C3V9Q-13-F can withstand before breakdown?

The BZX84C3V9Q-13-F has a nominal Zener voltage of 3.9 V at 5.0 mA test current, with a specified minimum breakdown voltage of 3.7 V and maximum of 4.1 V. It is not rated for forward conduction beyond 0.9 V at 10 mA; reverse operation below 1.0 V yields ≤3.0 µA leakage, and breakdown is intentionally initiated above 3.7 V in regulation mode.

Is BZX84C3V9Q-13-F suitable for use in a 5 V rail overvoltage clamp?

Yes - with a 3.9 V nominal Zener voltage and 4.1 V maximum at I_ZT, it clamps reliably below 4.2 V, providing margin against 5 V rail transients. Its 350 mW rating supports up to ~85 mA peak clamping current (P = V × I), making it appropriate for low-energy surges in 5 V logic or interface circuits.

How does the "Q" suffix in BZX84C3V9Q-13-F affect its specifications?

The "Q" denotes AEC-Q101 qualification, confirming compliance with automotive reliability stress tests including HTOL, TCT, and ESD. Electrically and thermally, it matches the standard BZX84C3V9-13-F, but undergoes additional screening and traceability controls required for automotive production use.

Can BZX84C3V9Q-13-F be used in place of a 3.3 V Zener diode?

No - its nominal regulation voltage is 3.9 V (range 3.7–4.1 V), which exceeds typical 3.3 V rail tolerances. Substituting it for a 3.3 V Zener would result in insufficient clamping or incorrect reference voltage. For 3.3 V applications, BZX84C3V3Q-13-F (3.3 V nominal, 3.1–3.5 V range) is the functionally matched automotive-grade variant.