Nexperia USA Inc. BZB84-C3V9-QR

Overview

BZB84-C3V9-QR from Nexperia is a dual Zener diode in SOT23 package with common-anode configuration, rated for 3.9 V nominal Zener voltage (±5 % tolerance), 300 mW total power dissipation, and AEC-Q101 qualification for automotive voltage regulation and clamping functions.

For engineers reviewing the BZB84-C3V9-QR datasheet, BZB84-C3V9-QR pinout, BZB84-C3V9-QR application, or BZB84-C3V9-QR equivalent, this device supports dual-rail reference generation, overvoltage protection in infotainment power supplies, and bidirectional ESD clamping in CAN/LIN transceiver interfaces where space-constrained dual-Zener functionality is required.

Technical Context

This dual common-anode Zener diode integrates two independent 3.9 V Zener junctions sharing a single anode terminal, enabling symmetrical clamping or complementary reference generation without external node tying. Its differential resistance is ≤90 Ω at I_Z = 5 mA, supporting stable regulation under moderate load variation.

The device operates across −55 °C to +150 °C ambient, with thermal resistance from junction to solder point of 100 K/W, and exhibits a temperature coefficient of −3.5 to 0.0 mV/K - indicating near-zero drift near room temperature for precision biasing applications.

Key Specifications

Pinout & Package

SOT23 plastic surface-mount package (2.9 mm × 1.3 mm × 1.0 mm body, 1.9 mm pin pitch) with gull-wing leads; optimized for reflow soldering on FR4 PCBs with standard footprint per Figure 12.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZB84-C3V9-QR, DMN3026LSD-13 serves power switching-not regulation-while BZX84-C3V9 delivers half the functional density and doubles assembly cost for dual-rail designs, making the BZB84-QR uniquely suited for space- and cost-sensitive automotive dual-clamp applications.

Availability

BZB84-C3V9-QR is available at Aetrix Electronics and suitable for automotive infotainment systems, engine control units, and industrial programmable logic controllers requiring stable component supply with AEC-Q101 compliance and SOT23 footprint compatibility.

Supply support for BZB84-C3V9-QR 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.

BZB84-QR belongs to Nexperia's AEC-Q101-qualified Zener diode product line, engineered specifically for compact, robust voltage regulation and transient protection in harsh automotive environments.

FAQ

What is the maximum continuous reverse current the BZB84-C3V9-QR can sustain at 25 °C?

The device supports a maximum continuous reverse current of 200 mA per diode, derived from its 300 mW total power dissipation limit and 3.9 V Zener voltage (P = V × I → I = 300 mW / 3.9 V ≈ 77 mA). However, the Absolute Maximum Rating specifies 200 mA forward current - reverse current capability is governed by thermal limits and derating curves in Figure 1, with practical continuous operation limited to ~75 mA at 25 °C ambient on standard FR4.

Can BZB84-C3V9-QR be used for bidirectional signal clamping in RS-485 interfaces?

Yes - with the common anode (Pin 3) tied to the local V_CC rail, Cathode 1 (Pin 1) clamps signals above V_CC + 3.9 V, and Cathode 2 (Pin 2) clamps signals below GND − 3.9 V. This configuration meets IEC 61000-4-2 Level 4 ESD requirements for RS-485 transceivers, provided layout minimizes trace inductance and uses appropriate series termination.

How does the ±5 % tolerance affect regulation accuracy in a 3.3 V LDO feedback network?

When used as a shunt reference in an LDO feedback divider, the ±5 % V_Z tolerance (3.7–4.1 V) introduces up to ±1.2 % output voltage error at the LDO's regulated rail. For example, a 3.3 V output may vary from 3.26 V to 3.34 V depending on unit-to-unit Zener variation - acceptable for non-precision loads but insufficient for ADC references requiring <±0.1 % stability.

Is the SOT23 package of BZB84-C3V9-QR compatible with standard automated optical inspection (AOI) systems?

Yes - the SOT23 outline (Figure 11) features defined gull-wing lead geometry, coplanarity ≤0.15 mm, and matte tin plating compliant with IPC-A-610 Class 2/3. Its 1.9 mm pin pitch and 0.45 mm lead thickness meet standard AOI camera resolution and lighting requirements for solder joint void detection and alignment verification in high-volume automotive PCB assembly.