Nexperia USA Inc. BZX38450-C43F

Overview

BZX38450-C43F 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 43 V regulation at 50 µA test current, with ±5 % tolerance, 300 mW total power dissipation, and 375 Ω differential resistance at 2 mA - enabling stable operation in battery-powered sensor nodes and portable instrumentation.

For engineers reviewing the BZX38450-C43F datasheet, BZX38450-C43F pinout, BZX38450-C43F application, or BZX38450-C43F equivalent, key selection criteria include its low 50 µA regulation current, 43 V nominal Zener voltage with tight ±5 % tolerance, SOD323 footprint compatibility, thermal resistance of 415 K/W (junction-to-ambient), and intentional leakage optimization for noise-sensitive analog front-ends.

Technical Context

This device operates as a two-terminal shunt voltage regulator, maintaining a stable 43 V reverse breakdown across its cathode-anode terminals under controlled current conditions. Its Zener voltage is specified at I_Z = 50 µA, with differential resistance of 375 Ω at I_Z = 2 mA and temperature coefficient of +0.05 mV/K - indicating minimal drift over temperature in low-bias configurations.

The BZX38450-C43F belongs to the "C" tolerance series (±5 %), features optimized leakage current for fast switching and reduced noise per AN90031, and is rated for 150 °C maximum junction temperature with 40 W non-repetitive peak reverse power capability at 100 µs pulse width.

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, single-sided copper FR4 mounting. Cathode identified by marking bar.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX38450-C43F, the BZX38450-B43 offers tighter initial accuracy at higher cost and identical thermal limits, while the MMSZ5268ET1G trades smaller size for greater power handling and less optimal noise performance - making the C43F optimal for space-constrained, ultra-low-power, noise-sensitive Zener references.

Availability

BZX38450-C43F is available at Aetrix Electronics and suitable for portable medical devices, industrial sensor nodes, battery management systems, and automotive body electronics requiring stable component supply with guaranteed long-term continuity.

Supply support for BZX38450-C43F 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 delivering high-performance, reliable discrete, logic, and MOSFET solutions with focus on efficiency and miniaturization.

The BZX38450 series belongs to Nexperia's low-current Zener regulator portfolio, engineered specifically for energy-efficient biasing and voltage referencing in space- and power-constrained applications such as wearables, IoT endpoints, and portable instrumentation.

FAQ

What is the maximum continuous reverse power this diode can handle at 70 °C ambient?

At 70 °C ambient, the BZX38450-C43F must be derated from its 300 mW rating at 25 °C using the 415 K/W thermal resistance. The allowable power drops to approximately 195 mW - calculated as (150 °C − 70 °C) / 415 K/W - ensuring junction temperature remains within the 150 °C limit under steady-state conditions.

Can this Zener be used in forward conduction mode for ESD protection?

Yes - the BZX38450-C43F has a forward voltage ≤ 0.9 V at 10 mA, making it suitable as a low-clamp forward path in bidirectional TVS configurations. However, its primary design intent is reverse-biased regulation; for dedicated ESD protection, Nexperia's dedicated ESD arrays (e.g., PESD series) offer superior clamping performance and certified IEC 61000-4-2 ratings.

How does the "C" suffix affect temperature coefficient behavior compared to "B" variants?

The "C" suffix denotes ±5 % tolerance and correlates with a specific process variant that exhibits a consistent +0.05 mV/K temperature coefficient across the 43 V rating - unlike "B" parts which show wider coefficient spread (e.g., BZX38450-B43: −2.7 to +0.4 mV/K). This tighter TC improves predictability in temperature-varying reference circuits.

Is the SOD323 footprint compatible with automated optical inspection (AOI) systems?

Yes - the SOD323 package features clearly defined cathode marking (bar), consistent 1.3 mm lead pitch, and standardized 1.7 mm × 1.25 mm body dimensions per JEDEC MO-203AB. These characteristics are fully supported by industry-standard AOI algorithms for polarity verification, solder joint quality, and placement accuracy in high-volume SMT lines.