Nexperia USA Inc. BZX384-A4V3X

Overview

BZX384-A4V3X from Nexperia is a ±1 % tolerance Zener voltage regulator diode in SOD323 (SC-76) package, rated for 4.3 V nominal breakdown voltage at 5 mA, 300 mW total power dissipation, and 40 W non-repetitive peak reverse power. It serves as a precision reference or overvoltage clamp in low-power analog signal conditioning and power rail stabilization circuits.

For engineers reviewing the BZX384-A4V3X datasheet, BZX384-A4V3X pinout, BZX384-A4V3X application, or BZX384-A4V3X equivalent, key selection criteria include its 4.3 V ±1 % regulation accuracy, 90 Ω max differential resistance at 5 mA, 3 μA max reverse current at 3.4 V, and thermal resistance of 415 K/W in free air - critical for compact PCB designs requiring stable low-current biasing.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain a stable reference voltage across its terminals under varying load and temperature conditions. Its 4.3 V nominal Zener voltage is specified at I_Z = 5 mA with ±1 % tolerance, and it exhibits a temperature coefficient of −3.5 mV/K in the 2.4 V–4.7 V range.

The device features low forward voltage (≤0.9 V at 10 mA), high surge capability (40 W non-repetitive peak reverse power for 100 μs), and junction-to-ambient thermal resistance of 415 K/W on FR4 PCB - enabling reliable operation in space-constrained consumer and industrial control applications.

Key Specifications

Pinout & Package

SOD323 (SC-76) plastic surface-mounted package with cathode marked by a bar on the top surface; compact 1.35 mm × 0.8 mm body, 0.45 mm pin pitch, and tin-plated terminations compatible with reflow and wave soldering per IPC-J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5229BS-7-F and BZX384-C4V3-TP, BZX384-A4V3X delivers superior regulation accuracy (±1 % vs. ±5 %), lower differential resistance (90 Ω vs. ≥150 Ω), and identical surge robustness - making it optimal for precision analog references where voltage stability is critical.

Availability

BZX384-A4V3X is available at Aetrix Electronics and suitable for power supply reference, overvoltage clamp, and signal level translation applications requiring stable component supply, consistent parametric performance, and long-term manufacturing continuity.

Supply support for BZX384-A4V3X 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 leadership in automotive-qualified and industrial-grade components.

The BZX384 series belongs to Nexperia's precision Zener diode product line, engineered specifically for low-power voltage reference and clamping in space-constrained consumer, industrial, and computing applications.

FAQ

What is the maximum continuous reverse current the BZX384-A4V3X can sustain?

The BZX384-A4V3X has no defined maximum continuous reverse current rating; instead, its safe operating limit is governed by total power dissipation. At 25 °C ambient on FR4 PCB, it sustains up to 69.8 mA continuously (300 mW ÷ 4.3 V) before exceeding 300 mW P_tot. Derating applies above 25 °C per the 415 K/W thermal resistance.

Can BZX384-A4V3X be used in place of a 4.3 V TL431 shunt regulator?

No - the BZX384-A4V3X is a passive two-terminal Zener diode, while the TL431 is an active three-terminal adjustable shunt regulator with 2.5 V reference and amplifier feedback. The Zener lacks current-sinking capability, gain, or programmability, making it unsuitable for precision feedback loops requiring dynamic regulation.

Does the BZX384-A4V3X meet RoHS and REACH compliance requirements?

Yes - Nexperia confirms BZX384-A4V3X complies with EU RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006, including SVHC screening. Full compliance documentation, including material declarations and test reports, is available via Nexperia's official product page and Aetrix Electronics' quality portal.

How does the −3.5 mV/K temperature coefficient affect regulation accuracy over temperature?

At 4.3 V nominal, a −3.5 mV/K coefficient causes ~−0.35 V drift over a 100 K rise (e.g., −40 °C to +60 °C), resulting in ~−8.1 % relative change. This is mitigated by using the diode near its zero-TC point (≥5.6 V types) or incorporating compensation in the circuit; for 4.3 V use, expect ±0.2 V variation across full −65 °C to +150 °C junction range.