Nexperia USA Inc. BZX84W-C20F

Overview

BZX84W-C20F 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 150 °C maximum junction temperature. It serves as a precision reference or overvoltage clamp in low-power analog signal conditioning and power rail stabilization circuits.

For engineers reviewing the BZX84W-C20F datasheet, BZX84W-C20F pinout, BZX84W-C20F application, or BZX84W-C20F equivalent, key selection criteria include Zener voltage tolerance (±5 %), differential resistance (≤55 Ω at I_Z = 5 mA), temperature coefficient (+16.4 mV/K), reverse leakage (≤200 nA at V_R = 14 V), and thermal resistance (455 K/W).

Technical Context

This Zener diode operates in reverse breakdown to maintain stable voltage across its cathode-anode terminals under regulated current conditions. Its ±5 % tolerance (C-series) and 20 V nominal Zener voltage are specified at I_Z = 5 mA with typical differential resistance of 55 Ω and positive temperature coefficient of +16.4 mV/K.

The device uses silicon planar technology in a leadless SOT323 package with two active terminals (anode and cathode) and one not-connected terminal. Thermal performance is characterized by R_th(j-a) = 455 K/W on FR4 PCB with single-sided copper, limiting continuous power handling to 275 mW at T_amb = 25 °C.

Key Specifications

Pinout & Package

SOT323 (SC-70) plastic surface-mounted package with 3 leads; dimensions per IEC JEDEC outline: 2.2 mm × 1.35 mm × 0.95 mm height; lead pitch 0.65 mm; tin-plated terminations compatible with standard reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84W-C20F, MMBZ5242B offers higher power handling but sacrifices board-area efficiency, while BZX84-C20 provides nearly identical performance in the same footprint with slightly improved leakage and thermal resistance-making it suitable for direct substitution in space-constrained designs requiring marginal reliability uplift.

Availability

BZX84W-C20F is available at Aetrix Electronics and suitable for industrial sensor interfaces, portable instrumentation power rails, and automotive body-control module voltage references requiring stable component supply and full traceability.

Supply support for BZX84W-C20F 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 high-volume, high-reliability discrete and logic devices, with manufacturing rooted in process excellence and automotive-grade quality systems.

The BZX84W series belongs to Nexperia's general-purpose Zener diode product line, designed specifically for compact, cost-sensitive voltage regulation and clamping in consumer, industrial, and communications equipment where SMT footprint and parametric consistency are critical.

FAQ

What is the maximum continuous Zener current for BZX84W-C20F at 70 °C ambient?

At T_amb = 70 °C, derated power dissipation is 185 mW (using linear derating from 275 mW at 25 °C to 0 W at 150 °C). With V_Z ≈ 20 V, maximum continuous Zener current is 9.25 mA. Exceeding this risks thermal runaway due to positive temperature coefficient and insufficient heat removal from the SOT323 package.

Can BZX84W-C20F be used in series to achieve higher reference voltages?

Yes, but with caution: series connection increases total dynamic impedance (sum of individual r_dif) and temperature coefficient (sum of individual S_Z). For two BZX84W-C20F diodes, combined V_Z ≈ 40 V ±10 %, r_dif ≈ 110 Ω, and S_Z ≈ +32.8 mV/K-requiring careful thermal management and current balancing resistors to prevent current hogging.

Is the not-connected pin (Pin 2) electrically isolated or tied internally?

Pin 2 is fully electrically isolated-no internal connection to die, substrate, or other terminals. It is a mechanical stub for package symmetry and must remain unconnected on the PCB. Routing traces or applying solder paste to Pin 2 introduces risk of mechanical stress fracture or unintended capacitive coupling in high-frequency layouts.

How does the 1.5 pF junction capacitance affect high-frequency noise suppression?

At 100 MHz, the 1.5 pF junction capacitance yields ~1.06 kΩ impedance, making BZX84W-C20F ineffective as a shunt RF filter above ~10 MHz. It functions reliably as a low-frequency clamp (<1 MHz) but requires parallel ceramic capacitors (e.g., 100 pF X7R) for broadband EMI suppression in switching power supply feedback paths.