Nexperia USA Inc. BZX84W-C20-QX

Overview

BZX84W-C20-QX from Nexperia is a ±5% tolerance Zener voltage regulator diode in SOT323 (SC-70) package, rated for 20 V nominal Zener voltage at 5 mA, 275 mW total power dissipation, and qualified to AEC-Q101 for automotive use. It provides stable voltage reference in low-power regulation and overvoltage protection circuits.

For engineers reviewing the BZX84W-C20-QX datasheet, BZX84W-C20-QX pinout, BZX84W-C20-QX application, or BZX84W-C20-QX equivalent, key selection criteria include Zener voltage tolerance (±5%), differential resistance (225 Ω at 5 mA), temperature coefficient (+16.4 mV/K), junction-to-ambient thermal resistance (455 K/W), and automotive qualification status.

Technical Context

This Zener diode operates in reverse breakdown mode with a nominal Zener voltage of 20 V at I_Z = 5 mA and exhibits a positive temperature coefficient of +16.4 mV/K, indicating increasing Zener voltage with rising temperature. Its differential resistance is 225 Ω at 5 mA, supporting stable regulation under moderate current variation.

The device is designed for surface-mount operation on FR4 PCBs with single-sided copper, delivering 275 mW total power dissipation and withstanding non-repetitive peak reverse power up to 40 W for 100 µs pulses. It features a 1.5 pF diode capacitance at 1 MHz and 0 V reverse bias, enabling use in high-frequency stabilization roles.

Key Specifications

Pinout & Package

Package: SOT323 (SC-70), leadless surface-mount plastic package with 3 terminals, 1.3 mm × 1.8 mm footprint, 0.65 mm pitch, and 0.45 mm max height.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84W-C20-QX, BZX84W-B20-Q offers improved voltage accuracy at identical form factor and qualification, while MMSZ5248B-TP trades automotive compliance for higher power and larger package size-making the original optimal for space-constrained, safety-critical automotive voltage references.

Availability

BZX84W-C20-QX is available at Aetrix Electronics and suitable for automotive ECUs, industrial sensor interfaces, and medical battery monitoring systems requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for BZX84W-C20-QX 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

Nexperia is a global semiconductor expert focused on essential efficiency technologies, delivering high-performance logic, discrete, and MOSFET solutions for automotive, industrial, and consumer markets.

The BZX84W-Q series belongs to Nexperia's automotive-qualified Zener diode product line, engineered specifically for reliable voltage regulation and transient suppression in harsh-environment electronic control units.

FAQ

What is the maximum continuous reverse current this diode can handle?

The BZX84W-C20-QX has a maximum forward current rating of 200 mA, but its continuous reverse (Zener) current is limited by power dissipation: at 20 V, the absolute maximum DC Zener current is 13.75 mA (275 mW ÷ 20 V). Operation above this requires derating per thermal resistance (455 K/W) and ambient temperature.

Is Pin 2 electrically functional or a mechanical dummy lead?

Pin 2 is explicitly designated "n.c." (not connected) in Nexperia's official pinning documentation and graphic symbol. It is an internal dummy lead with no electrical connection to the die-PCB pads must remain unconnected and un-soldered to avoid mechanical stress or unintended parasitic coupling.

How does the +16.4 mV/K temperature coefficient affect circuit design?

This positive temperature coefficient means the Zener voltage increases by ~16.4 mV per °C rise in junction temperature. In temperature-sensitive applications like precision references, designers must account for self-heating and ambient drift-e.g., at 100 °C junction temperature, V_Z rises ~1.2 V above its 25 °C value, shifting regulation point predictably.

Can this diode be used in parallel for higher power handling?

No-Zener diodes exhibit negative resistance characteristics and cannot be reliably paralleled without individual current-limiting resistors. Even with matched units, minor V_Z variations cause current hogging. For higher power, select a single higher-rated Zener (e.g., BZX84W-C20-Q with same specs but different package) or use active regulation instead.