Nexperia USA Inc. BZX84W-C3V0-QX

Overview

BZX84W-C3V0-QX from Nexperia is a ±5% tolerance Zener diode in SOT323 (SC-70) package, rated for 3.0 V nominal regulation voltage at 5 mA, with 95 Ω differential resistance and −2.1 mV/K temperature coefficient. It delivers 275 mW total power dissipation on FR4 PCB and supports automotive-grade voltage reference and overvoltage clamping in compact DC-DC feedback paths.

For engineers reviewing the BZX84W-C3V0-QX datasheet, BZX84W-C3V0-QX pinout, BZX84W-C3V0-QX application, or BZX84W-C3V0-QX equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (455 K/W), reverse leakage (10 µA at 1 V), junction temperature limit (150 °C), and AEC-Q101 qualification for under-hood electronics.

Technical Context

This Zener diode operates in reverse breakdown to maintain stable 3.0 V reference across load and line variations, with low dynamic impedance enabling precise regulation in low-current bias networks. Its −2.1 mV/K temperature coefficient minimizes drift over −55 °C to +150 °C ambient range.

The device features non-connected terminal (Pin 2), anode (Pin 1), and cathode (Pin 3), optimized for high-frequency decoupling due to 6 pF junction capacitance at 0 V and fast transient response. It sustains non-repetitive 40 W surge power for 100 µs pulses per IEC 60134 limiting values.

Key Specifications

Pinout & Package

SOT323 (SC-70) leadless surface-mount plastic package: 1.35 mm × 1.75 mm footprint, 0.95 mm height, 0.65 mm lead pitch, tin-plated terminations compatible with reflow and wave soldering per JEDEC MS-012.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84W-B3V0-Q, the C3V0-QX trades 0.12 V regulation window for broader manufacturing yield; versus MMSZ4684T1G, it delivers automotive reliability and 40% smaller footprint at comparable cost, but with lower absolute power handling.

Availability

BZX84W-C3V0-QX is available at Aetrix Electronics and suitable for automotive engine control, infotainment power sequencing, and industrial PLC analog input protection requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for BZX84W-C3V0-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 high-volume, high-reliability essential semiconductors-including logic, discretes, MOSFETs, and bipolar devices-with manufacturing rooted in process technology leadership and automotive-grade quality systems.

The BZX84W-Q series belongs to Nexperia's automotive-qualified Zener diode product line, engineered specifically for robust voltage reference and transient suppression in harsh-environment electronic control units where AEC-Q101 compliance and thermal stability are mandatory.

FAQ

What is the maximum continuous reverse current this Zener can handle at 3.0 V?

The BZX84W-C3V0-QX is not rated for continuous reverse conduction at its Zener voltage. Its specified operating condition is I_Z = 5 mA for V_Z measurement. The absolute maximum reverse current is limited by P_tot = 275 mW, yielding ~91 mA at 3.0 V-but sustained operation above 5 mA degrades regulation accuracy and accelerates thermal aging. Designers must limit average Zener current to ≤5 mA for stable reference performance.

Can Pin 2 be used as a heatsink or grounded for thermal improvement?

No-Pin 2 is internally not connected (n.c.) and electrically isolated. Connecting it to ground, V_CC, or a heatsink introduces no thermal benefit and risks mechanical stress on the die attach or contamination of the internal cavity. Thermal performance relies solely on copper pad area and solder joint quality on Pins 1 and 3 per the SOT323 reflow footprint in Figure 9.

How does the −2.1 mV/K temperature coefficient affect regulation in a 125 °C under-hood environment?

From 25 °C to 125 °C ambient (ΔT = 100 K), the Zener voltage shifts by −2.1 mV/K × 100 K = −0.21 V. With nominal V_Z = 3.0 V, this yields ~2.79 V at 125 °C. Combined with ±5% initial tolerance (2.80–3.20 V), the full operating range becomes 2.59–3.20 V-still sufficient for most reset threshold and biasing applications where 3.0 V ±0.3 V is acceptable.

Is this part suitable for replacing older BZX84-C3V3 in existing designs?

No-BZX84W-C3V0-QX has 3.0 V nominal Zener voltage versus 3.3 V for BZX84-C3V3, resulting in a 0.3 V system-level offset. While both use SOT23 packages, the BZX84W series uses SOT323 (smaller) and features improved AEC-Q101 qualification, tighter thermal specs, and different marking codes. Direct replacement requires circuit validation for voltage margin, footprint compatibility, and thermal derating.