Nexperia USA Inc. BZX84-B10/DG/B3,21

Overview

BZX84-B10/DG/B3,21 from Nexperia is a ±2 % tolerance Zener voltage regulator diode in SOT23 (TO-236AB) package, rated for 10 V nominal breakdown voltage at 5 mA test current, 250 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 supply rails and signal conditioning circuits.

For engineers reviewing the BZX84-B10/DG/B3,21 datasheet, BZX84-B10/DG/B3,21 pinout, BZX84-B10/DG/B3,21 application, or BZX84-B10/DG/B3,21 equivalent, key selection criteria include Zener voltage tolerance (±2 %), thermal resistance (330 K/W junction-to-solder-point), differential resistance (≤150 Ω at IZ = 5 mA), and reverse leakage (<2 μA at VR = 7.6 V).

Technical Context

This device operates in reverse-biased Zener breakdown mode with a specified 10 V nominal working voltage at 5 mA, exhibiting a temperature coefficient of +4.5 mV/K - indicating positive drift with rising junction temperature. Its low 250 mW steady-state power rating requires careful thermal management on FR4 PCBs.

The SOT23 package features three terminals: anode (Pin 1), unconnected (Pin 2), and cathode (Pin 3), enabling compact placement in space-constrained voltage reference paths. Non-repetitive surge capability supports transient suppression up to 40 W for 100 μs pulses at Tj = 25 °C.

Key Specifications

Pinout & Package

Package: SOT23 (TO-236AB), surface-mount plastic package with 3 leads, 1.9 mm × 1.1 mm footprint, 1.2 mm height, and standard reflow-compatible solder pads per Figure 12.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5240B and BZX84-C10, the BZX84-B10/DG/B3,21 delivers tighter voltage control (±2 % vs. ±5 %) and lower dynamic impedance (≤150 Ω vs. ≤200–300 Ω), making it preferable for precision reference and low-drift biasing where thermal headroom is limited.

Availability

BZX84-B10/DG/B3,21 is available at Aetrix Electronics and suitable for industrial power supplies, sensor interface circuits, and embedded system voltage monitoring requiring stable component supply and consistent parametric performance across production batches.

Supply support for BZX84-B10/DG/B3,21 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 manufacturer headquartered in Nijmegen, Netherlands, specializing in high-volume logic, discrete, and MOSFET solutions with emphasis on reliability and manufacturability.

The BZX84 series belongs to Nexperia's precision Zener diode product line, designed specifically for low-power voltage reference, clamping, and regulation in consumer, industrial, and communication equipment where SMT scalability and parametric consistency are critical.

FAQ

What is the maximum continuous reverse current this diode can sustain at 10 V?

The BZX84-B10/DG/B3,21 is not rated for continuous reverse current at its Zener voltage. At VZ = 10 V, it operates in breakdown with a nominal test current of 5 mA. Sustained operation above 5 mA requires derating per thermal limits - maximum steady-state power is 250 mW, so continuous IZ must stay ≤25 mA at 10 V to avoid exceeding Ptot, assuming ideal heat sinking.

Can Pin 2 be used as a thermal pad or grounded for improved thermal performance?

No. Pin 2 is explicitly marked "n.c." (not connected) in the official pinning diagram and has no internal connection. Routing it to ground or using it as a thermal pad provides no electrical or thermal benefit and may risk solder bridging or unintended parasitic coupling in high-impedance reference circuits.

How does the +4.5 mV/K temperature coefficient affect circuit stability over −40 °C to +85 °C?

Over that range, the Zener voltage shifts by approximately +0.54 V (4.5 mV/K × 120 K), resulting in a VZ span of ~9.8 V to ~10.34 V. This drift must be accommodated in feedback networks or compensated via complementary components - it is not negligible in 1 % accuracy systems.

Is this part qualified for automotive applications?

No. Per Nexperia's Revision 7 datasheet (January 2023), the BZX84-B10/DG/B3,21 is explicitly designated as non-automotive qualified. Automotive-grade alternatives (e.g., BZX84-Q series) undergo additional AEC-Q101 stress testing and are separately documented - this part lacks those qualifications and warranty coverage for automotive use.