Diodes Incorporated BZX84C3V9W-7-F

Overview

BZX84C3V9W-7-F from Diodes Incorporated is a 3.9 V, 200 mW surface-mount Zener diode in SOT-323 package, rated for 5 mA test current with 90 Ω dynamic impedance at 1 kHz and 3.0 µA maximum reverse leakage at 1.0 V, used for precision voltage regulation and reference in low-power analog circuits.

For engineers reviewing the BZX84C3V9W-7-F datasheet, BZX84C3V9W-7-F pinout, BZX84C3V9W-7-F application, or BZX84C3V9W-7-F equivalent, key selection criteria include nominal Zener voltage tolerance (±5.1%), temperature coefficient (−3.5 to 0 mV/°C), thermal resistance (625 K/W), and RoHS-compliant lead-free plating on Alloy 42 leadframe.

Technical Context

This Zener diode operates in reverse breakdown mode with a specified nominal Zener voltage of 3.9 V at 5 mA test current, maintaining regulation across −65 °C to +125 °C ambient temperature range. Its planar die construction ensures stable voltage reference performance under low-current conditions.

It exhibits 90 Ω Zener impedance at 1 kHz and 5 mA, 600 Ω at knee current (1.0 mA), and 3.0 µA reverse leakage at VR = 1.0 V - characteristics critical for low-noise biasing and feedback networks in voltage references and power supply supervision.

Key Specifications

Pinout & Package

Package: SOT-323 - ultra-small surface-mount plastic case (2.0–2.2 mm length × 1.2–1.4 mm width × 0.9–1.0 mm height), UL 94V-0 rated, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5227BS-7-F and 1SMA5913BT3G, BZX84C3V9W-7-F offers optimal balance of voltage accuracy (±5.1%), miniature SOT-323 size, and 200 mW dissipation for space-constrained, low-power analog signal chains.

Availability

BZX84C3V9W-7-F is available at Aetrix Electronics and suitable for low-power voltage reference, ESD protection, LDO feedback, and bias generation applications requiring stable component supply and full traceability.

Supply support for BZX84C3V9W-7-F 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.

This device belongs to the BZX84C series of precision Zener diodes designed specifically for compact, low-power voltage regulation and clamping in consumer, computing, and industrial electronics.

FAQ

What is the maximum reverse voltage before breakdown for BZX84C3V9W-7-F?

The nominal Zener voltage is 3.9 V at 5 mA test current, with guaranteed breakdown occurring between 3.7 V and 4.1 V. Below 3.7 V, reverse leakage remains ≤3.0 µA at 1.0 V; no hard "maximum reverse voltage" is defined outside this regulated range.

Can BZX84C3V9W-7-F be used in place of a 3.3 V Zener diode?

No - its nominal voltage is 3.9 V with a 3.7–4.1 V range, making it unsuitable as a direct replacement for 3.3 V Zeners like BZX84C3V3W. Substituting would raise regulated voltage by ~0.6 V, potentially exceeding IC absolute maximum ratings.

Is the SOT-323 package compatible with standard reflow profiles?

Yes - the device is qualified for lead-free reflow per J-STD-020D Level 1 moisture sensitivity, supporting peak temperatures up to 260 °C. Its 0.006 g mass and plastic body allow compatibility with standard Pb-free reflow profiles without delamination risk.

Does BZX84C3V9W-7-F have a specified capacitance value?

No specific capacitance is provided in the datasheet for this part. Figure 4 shows typical total capacitance vs. nominal Zener voltage, estimating ~30–40 pF for 3.9 V devices at VR = 1 V, but no guaranteed min/max is specified - design margins should assume ≤50 pF.