Nexperia USA Inc. BZX38450-B10X

Overview

BZX38450-B10X from Nexperia is a low-current Zener voltage regulator diode in SOD323 (SC-76) package, designed for precision voltage reference and biasing in ultra-low-power circuits. It delivers a nominal 10 V regulation at 50 µA test current, with ±2 % tolerance, 300 mW total power dissipation, and 90 Ω typical differential resistance at 5 mA - enabling stable operation in portable battery-powered sensors and microcontroller reset circuits.

For engineers reviewing the BZX38450-B10X datasheet, BZX38450-B10X pinout, BZX38450-B10X application, or BZX38450-B10X equivalent, key selection criteria include its low 50 µA regulation current, tight ±2 % tolerance, SOD323 footprint compatibility, and optimized leakage behavior for noise-sensitive analog front-ends and low-quiescent-power voltage monitoring.

Technical Context

This Zener diode operates in reverse breakdown mode with a specified working voltage of 10 V (min 9.8 V, max 10.2 V) at I_Z = 50 µA. Its differential resistance is ≤150 Ω at 5 mA, and temperature coefficient is +4.5 mV/K - indicating positive drift over temperature, critical for thermal stability analysis in reference designs.

The device features intentional minor leakage current enhancement per AN90031 to improve switching speed and reduce noise in dynamic bias networks. It is rated for junction temperatures up to 150 °C and ambient operating range from −55 °C to +150 °C, with thermal resistance R_th(j-a) = 415 K/W in free air on FR4 PCB.

Key Specifications

Pinout & Package

SOD323 (SC-76) surface-mount plastic package: 1.7 mm × 1.25 mm × 0.95 mm body, 1.3 mm lead pitch, cathode marked by bar on top surface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5240B and BZX384-C10, the BZX38450-B10X provides tighter ±2 % regulation, higher 300 mW power headroom, and lower leakage - making it optimal for battery-critical, noise-sensitive, and space-constrained precision reference designs where long-term stability and minimal quiescent draw are mandatory.

Availability

BZX38450-B10X is available at Aetrix Electronics and suitable for portable medical devices, industrial sensor nodes, and low-power microcontroller subsystems requiring stable component supply with guaranteed long-term manufacturability.

Supply support for BZX38450-B10X 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, logic, and MOSFET solutions for automotive, industrial, and consumer markets.

The BZX38450 series belongs to Nexperia's precision low-current Zener portfolio, engineered specifically for ultra-low-power voltage reference and biasing in battery-operated and thermally constrained applications.

FAQ

What is the maximum continuous reverse current the BZX38450-B10X can sustain without degradation?

The device is rated for a maximum forward current of 250 mA, but as a Zener regulator, its continuous reverse current is limited by power dissipation. At 25 °C ambient on FR4 PCB, sustained reverse current must stay below 30 mA to maintain ≤300 mW dissipation (10 V × 30 mA = 300 mW), assuming no additional thermal derating.

Does the BZX38450-B10X require a series resistor in all applications?

Yes - a current-limiting resistor is mandatory to set the operating Zener current within the 50 µA to 30 mA range. Without it, excessive current causes thermal runaway. The resistor value is calculated as R = (V_IN − 10 V) / I_Z, where I_Z is selected based on required regulation stability and power budget.

How does the BZX38450-B10X behave under pulsed overvoltage conditions?

It supports non-repetitive peak reverse power dissipation up to 40 W for 100 µs pulses at 25 °C junction temperature. This enables effective transient suppression in IEC 61000-4-5 surge events, provided pulse repetition rate remains low enough to avoid cumulative thermal stress beyond 150 °C junction limit.

Can the BZX38450-B10X be used in forward conduction mode?

Yes - its forward voltage is ≤0.9 V at 10 mA, making it suitable as a low-drop clamp or ESD protection diode in bidirectional signal lines. However, forward operation is secondary; its primary design intent and characterization are for reverse-biased Zener regulation at precisely defined current levels.