Nexperia USA Inc. BZX84W-C27X

Overview

BZX84W-C27X from Nexperia is a ±5 % tolerance Zener voltage regulator diode with nominal 27 V breakdown voltage, 300 Ω differential resistance at 2 mA, and 23.4 mV/K temperature coefficient, designed for precision voltage reference and overvoltage protection in compact SMT power management circuits.

For engineers reviewing the BZX84W-C27X datasheet, BZX84W-C27X pinout, BZX84W-C27X application, or BZX84W-C27X equivalent, this part serves as a stable 27 V shunt regulator in low-power analog rails, ESD-protected I/O clamping networks, and feedback path references where tight voltage tolerance and low capacitance (1.0 pF at 1 MHz) are critical.

Technical Context

This Zener diode operates in reverse-biased breakdown mode to maintain a stable 27 V reference across its cathode-anode terminals under regulated current conditions (IZ = 2 mA). Its ±5 % tolerance (C-series) balances cost and accuracy for non-critical regulation tasks.

Thermal performance is defined by a junction-to-ambient thermal resistance of 455 K/W on FR4 PCB, limiting continuous dissipation to 275 mW at 25 °C ambient. Non-repetitive surge capability reaches 40 W for 100 µs pulses, supporting transient suppression roles.

Key Specifications

Pinout & Package

Package: SOT323 (SC-70), leadless surface-mount plastic package with 3 terminals, footprint optimized for reflow soldering (2.65 mm × 2.35 mm body, 0.65 mm pitch).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84W-C27X, BZX84W-B27 offers superior voltage accuracy and lower dynamic impedance but at higher cost and slightly worse thermal coefficient; MMBZ5256BS provides identical nominal voltage but compromises high-frequency performance due to 30 pF capacitance and lacks the isolated n.c. pin for mechanical stability in fine-pitch layouts.

Availability

BZX84W-C27X is available at Aetrix Electronics and suitable for power supply reference design, I/O line protection, signal conditioning reference, and industrial sensor biasing requiring stable component supply across automotive-adjacent, industrial control, and test equipment programs.

Supply support for BZX84W-C27X 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, reliable discrete, logic, and MOSFET solutions for automotive, industrial, and consumer markets.

The BZX84W series belongs to Nexperia's general-purpose Zener diode product line, engineered for compact, cost-sensitive voltage regulation and protection in space-constrained SMT designs where reliability and consistent parametric performance are prioritized over automotive qualification.

FAQ

What is the maximum continuous reverse current the BZX84W-C27X can handle at 25 °C?

The device supports a maximum continuous reverse current of 10.2 mA, calculated from its 275 mW total power dissipation rating and 27 V nominal Zener voltage (P = V × I → I = 275 mW / 27 V ≈ 10.2 mA). This assumes no additional thermal derating and operation on a standard FR4 PCB with single-sided copper.

Does the n.c. pin (pin 2) require PCB routing or grounding?

No - pin 2 is internally not connected and must remain unconnected on the PCB. Routing or grounding it may cause mechanical stress or solder bridging risks due to the 0.65 mm pitch; the datasheet explicitly defines it as "not connected" with no internal bond wire or semiconductor link.

How does the +23.4 mV/K temperature coefficient affect regulation accuracy over temperature?

At a 50 °C ambient rise (e.g., 25 °C to 75 °C), the Zener voltage increases by approximately 1.17 V (23.4 mV/K × 50 K), shifting the nominal 27 V to ~28.17 V. This drift is linear and predictable, allowing firmware-based compensation in closed-loop systems where absolute accuracy is secondary to monotonic behavior.

Can BZX84W-C27X be used in place of a 24 V Zener for overvoltage protection?

No - substituting a 27 V Zener for a 24 V design violates the required clamping threshold. The BZX84W-C24 variant (22.8–25.6 V range) is the correct part for 24 V systems; using BZX84W-C27X would allow voltages up to 28.9 V before conduction, risking damage to downstream 24 V-rated components.