Nexperia USA Inc. BZX38450-C11X

Overview

BZX38450-C11X from Nexperia is a low-current Zener voltage regulator diode in SOD323 (SC-76) package, designed for precision biasing and voltage reference in ultra-low-power circuits. It delivers a nominal 11 V regulation at 50 µA test current, with ±5 % tolerance, 150 Ω typical differential resistance at 5 mA, and 8.4 mV/K temperature coefficient - enabling stable operation in portable battery-powered sensors and microcontroller reset circuits.

For engineers reviewing the BZX38450-C11X datasheet, BZX38450-C11X pinout, BZX38450-C11X application, or BZX38450-C11X equivalent, key selection criteria include its 50 µA regulation point, intentional leakage optimization for noise reduction, SOD323 thermal resistance (R_th(j-sp) = 110 K/W), and compatibility with FR4 PCBs using standard reflow footprints.

Technical Context

This Zener diode operates in reverse breakdown mode with a specified working voltage of 10.45 V to 11.55 V at I_Z = 50 µA. Its differential resistance remains ≤150 Ω at 5 mA, and it exhibits a positive temperature coefficient of +5.4 mV/K - supporting predictable drift compensation in analog references.

The device features intentionally elevated leakage current per AN90031 to suppress switching transients and reduce high-frequency noise. It is rated for 300 mW total power dissipation at T_amb ≤ 25 °C on single-sided FR4 PCBs and supports non-repetitive surge power up to 40 W for 100 µs pulses.

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 Zener voltage reference applications.

Compared with BZX38450-C11X, BZX384-B11 offers superior voltage accuracy but lacks noise-suppressing leakage tuning, while MMSZ5240B trades compact SOD323 size for greater thermal margin at the cost of PCB real estate and higher parasitic capacitance.

Availability

BZX38450-C11X is available at Aetrix Electronics and suitable for microcontroller reset circuits, portable sensor bias references, USB-C power negotiation clamps, and industrial PLC input protection requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for BZX38450-C11X 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 discrete and logic devices, serving automotive, industrial, and consumer markets with scalable manufacturing and rigorous quality systems.

The BZX38450 series belongs to Nexperia's low-current Zener regulator product line, engineered specifically for battery-powered and noise-sensitive applications where minimal bias current and controlled leakage behavior are critical design requirements.

FAQ

What is the maximum continuous power dissipation for BZX38450-C11X?

The BZX38450-C11X has a maximum total power dissipation of 300 mW at ambient temperatures ≤25 °C when mounted on a standard FR4 PCB with single-sided copper and tin plating. Derating is required above 25 °C per the R_th(j-a) = 415 K/W thermal resistance curve, reaching zero dissipation at 150 °C ambient.

How does the "C" suffix differ from "B" in the BZX38450 series?

The "C" suffix denotes ±5 % voltage tolerance and incorporates an intentional, controlled increase in reverse leakage current per application note AN90031 - optimized for faster switching response and reduced high-frequency noise. The "B" variant offers ±2 % tolerance and standard leakage, prioritizing voltage accuracy over noise performance.

Can BZX38450-C11X be used in place of a 1N4740A?

No - the 1N4740A is a 10 V, 1 W through-hole Zener with ±5 % tolerance and significantly higher power handling. BZX38450-C11X is a 11 V, 300 mW SMD device with different thermal characteristics, leakage behavior, and surge capability. Direct substitution requires validation of bias current, PCB thermal design, and transient immunity requirements.

What is the significance of the 50 µA test current specification?

The 50 µA test current reflects the device's intended operating point for ultra-low-power applications such as battery-backed memory retention or micropower sensor biasing. Regulation voltage is guaranteed at this current, enabling accurate modeling of voltage drop and power consumption in sub-100 µA systems where traditional 20 mA Zener test points would be impractical.