Nexperia USA Inc. BZX84W-C3V9F

Overview

BZX84W-C3V9F from Nexperia is a ±5 % tolerance Zener voltage regulator diode in SOT323 (SC-70) package, providing 3.9 V nominal regulation at 5 mA with 90 Ω differential resistance and −2.5 mV/K temperature coefficient. It delivers stable reference voltage for low-power biasing, overvoltage clamping, and signal-level voltage stabilization in compact consumer and industrial PCBs.

For engineers reviewing the BZX84W-C3V9F datasheet, BZX84W-C3V9F pinout, BZX84W-C3V9F application, or BZX84W-C3V9F equivalent, this page details its verified Zener characteristics, thermal performance on FR4, SC-70 terminal mapping, and substitution options for precision 3.9 V regulation under ≤200 mA forward current and ≤275 mW power dissipation.

Technical Context

This Zener diode operates in reverse breakdown to maintain a stable 3.9 V reference across load variations, with a typical differential resistance of 90 Ω at I_Z = 5 mA ensuring minimal output voltage drift under dynamic current conditions. Its negative temperature coefficient of −2.5 mV/K enables predictable thermal behavior in ambient ranges from −55 °C to +150 °C.

The device supports high-frequency applications due to low junction capacitance of 450 pF at f = 1 MHz and VR = 0 V, and withstands non-repetitive surge pulses up to 40 W (tp = 100 µs), making it suitable for transient suppression in signal conditioning paths and power rail monitoring circuits.

Key Specifications

Pinout & Package

SOT323 (SC-70) leadless surface-mount plastic package with 3 terminals; dimensions: 2.2 mm × 1.35 mm × 0.95 mm (L × W × H), standard footprint per Fig. 9 (reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84W-C3V9F, MMBZ5227BLT1G offers higher power handling at the cost of larger size, while BZX84-C3V9 provides identical regulation performance and mechanical fit-making it ideal for supply chain diversification without redesign.

Availability

BZX84W-C3V9F is available at Aetrix Electronics and suitable for power supply reference, signal-level clamping, low-power bias network, and high-frequency detector bias applications requiring stable component supply, consistent parametric performance, and long-term SMT manufacturability.

Supply support for BZX84W-C3V9F 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 delivering high-performance, reliable discrete, logic, and MOSFET devices optimized for efficiency and miniaturization in mass-market electronics.

The BZX84W series belongs to Nexperia's general-purpose Zener diode product line, engineered for compact, cost-sensitive voltage regulation and protection in consumer, industrial, and communications equipment where SOT323 footprint and ±2 %/±5 % tolerance options are critical.

FAQ

What is the maximum continuous reverse current the BZX84W-C3V9F can sustain in regulation mode?

The device is rated for Zener test current I_Z = 5 mA per datasheet characterization, but its absolute maximum limiting value is 200 mA forward current. In reverse breakdown, sustained current is constrained by P_tot = 275 mW: at 3.9 V, this yields ~70 mA maximum continuous Zener current before exceeding thermal limits on FR4.

Does Pin 2 (n.c.) require PCB routing or thermal relief?

No. Pin 2 is internally not connected and serves only as a mechanical anchor in the SOT323 package. It must remain electrically isolated-no trace, pad, or thermal via should connect to it. Standard reflow footprints allocate a 0.5 mm solder land solely for mechanical stability.

How does the −2.5 mV/K temperature coefficient affect long-term reference stability?

Over a 100 °C ambient range (−40 °C to +60 °C), the coefficient induces ~250 mV total drift (−2.5 mV/K × 100 K). This is inherent to the 3.9 V Zener bandgap and is fully characterized in Fig. 6; system-level compensation (e.g., matched NTC networks) is required only for sub-10 mV stability budgets.

Can BZX84W-C3V9F replace BZX84-C3V9 in existing designs?

Yes-both share identical electrical specifications (3.7–4.1 V V_Z, 90 Ω r_dif, 275 mW P_tot) and SOT323 package outline. The "W" suffix denotes updated wafer process and non-automotive qualification per Rev. 2 (Jan 2023); no layout or schematic changes are needed for drop-in replacement.