Nexperia USA Inc. BZX84W-C4V7-QX

Overview

BZX84W-C4V7-QX from Nexperia is a ±5 % tolerance Zener voltage regulator diode in SOT323 (SC-70) package, rated for 4.4 V to 5.0 V nominal Zener voltage at 5 mA, with 275 mW total power dissipation and 3 µA reverse current at 2 V, used for precision voltage reference and overvoltage protection in automotive power rails.

For engineers reviewing the BZX84W-C4V7-QX datasheet, BZX84W-C4V7-QX pinout, BZX84W-C4V7-QX application, or BZX84W-C4V7-QX equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (455 K/W), AEC-Q101 qualification, low capacitance (6 pF), and SOT323 footprint compatibility in space-constrained PCB layouts.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain stable voltage regulation under varying load and temperature conditions. Its differential resistance of 500 Ω at 5 mA and temperature coefficient of −1.4 mV/K (at I_Z = 5 mA) enable predictable drift behavior across −55 °C to +150 °C ambient range.

Designed for high-frequency applications, it exhibits 6 pF junction capacitance at 1 MHz and 0 V reverse bias, supporting fast transient response in feedback loops and ESD clamp circuits. The device is qualified per AEC-Q101 and mounted on FR4 PCB with single-sided copper, defining its thermal performance envelope.

Key Specifications

Pinout & Package

SOT323 (SC-70) leadless surface-mount plastic package with 3 terminals, 1.3 mm × 1.8 mm body size, 0.65 mm pitch, and 0.25 mm max A₁ height - optimized for automated placement and reflow soldering on dense PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84W-C4V7-QX, BZX84W-C4V7 omits automotive qualification and lot traceability, while MMSZ4705T1G trades miniaturization for higher power and thermal robustness - making the QX variant optimal for AEC-compliant, space-constrained designs requiring certified reliability.

Availability

BZX84W-C4V7-QX is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, and medical front-end biasing requiring stable component supply with full AEC-Q101 documentation and lot traceability.

Supply support for BZX84W-C4V7-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, reliable discrete and logic devices for automotive, industrial, and consumer markets.

BZX84W-Q series belongs to Nexperia's AEC-Q101-qualified Zener diode portfolio, engineered specifically for robust voltage regulation and transient suppression in harsh automotive environments.

FAQ

What is the maximum continuous reverse current this diode can sustain at 4.7 V?

The BZX84W-C4V7-QX is specified for Zener test current I_Z = 5 mA, with maximum continuous power dissipation of 275 mW. At 4.7 V, this corresponds to ~58.5 mA absolute upper limit (P_tot/V_Z), but operation above 5 mA increases differential resistance and temperature drift - design practice limits sustained current to ≤5 mA for stable regulation.

Does the "n.c." pin require grounding or thermal relief on the PCB?

No. Pin 2 is internally not connected and must remain electrically floating. Neither grounding nor thermal pad attachment is permitted - doing so risks mechanical stress or unintended parasitic coupling. The SOT323 footprint in Figure 9 shows no solder land or copper pour for pin 2.

How does the −1.4 mV/K temperature coefficient affect regulation accuracy over temperature?

At I_Z = 5 mA, the Zener voltage shifts −1.4 mV per Kelvin rise. Over a −40 °C to +125 °C range (165 K ΔT), total drift is −231 mV - approximately −4.9 % of nominal 4.7 V. This is factored into the ±5 % total tolerance band and remains within specification when combined with initial tolerance and aging effects.

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

No. Zener diodes exhibit manufacturing variations in V_Z and r_diff, causing current imbalance when paralleled - one device will dominate conduction and overheat. For higher power, select a single diode with appropriate P_tot rating (e.g., BZX84W-C4V7-QX is limited to 275 mW on FR4) or use active regulation instead.