Nexperia USA Inc. BZX38450-C9V1-QX

Overview

BZX38450-C9V1-Q from Nexperia is a low-current Zener voltage regulator diode in SOD323 (SC-76) package, rated for 9.1 V nominal regulation at 50 µA test current, with ±5 % tolerance, 300 mW total power dissipation, and AEC-Q101 qualification for automotive use.

For engineers reviewing the BZX38450-C9V1-Q datasheet, BZX38450-C9V1-Q pinout, BZX38450-C9V1-Q application, or BZX38450-C9V1-Q equivalent, this device serves as a precision low-bias voltage reference in battery-powered sensor nodes, automotive body control modules, and portable instrumentation where leakage-sensitive regulation is required.

Technical Context

This Zener diode operates in reverse breakdown mode with a specified working voltage of 8.65 V to 9.56 V at I_Z = 50 µA, exhibiting a temperature coefficient of +3.8 mV/K and differential resistance of 100 Ω at I_Z = 5 mA. Its low 50 µA test current enables stable regulation under ultra-low quiescent current conditions.

The device features intentional minor leakage current optimization per AN90031 for fast switching transients and reduced noise in signal conditioning paths. It is qualified to AEC-Q101 and rated for operation from −55 °C to +150 °C ambient, with junction-to-ambient thermal resistance of 415 K/W on FR4 PCB.

Key Specifications

Pinout & Package

Package: SOD323 (SC-76), surface-mounted plastic package; 2 leads; 1.3 mm pitch; 1.7 mm × 1.25 mm × 0.95 mm body; cathode marked by bar on top surface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX38450-C9V1-Q, the BZX38450-B9V1-Q offers tighter voltage control at the expense of higher dynamic impedance and slightly elevated leakage, while MMSZ5240B-TP trades automotive qualification and ultra-low leakage for higher power handling and broader commercial availability.

Availability

BZX38450-C9V1-Q is available at Aetrix Electronics and suitable for automotive body electronics, portable sensor interfaces, and medical wearable power monitoring requiring stable component supply with AEC-Q101 compliance and low-quiescent-current performance.

Supply support for BZX38450-C9V1-Q 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 leading semiconductor manufacturer specializing in high-performance, high-reliability discrete and logic devices, with global R&D and manufacturing infrastructure focused on automotive, industrial, and mobile markets.

The BZX38450-Q series belongs to Nexperia's AEC-Q101-qualified Zener diode product line, designed specifically for low-current voltage regulation in automotive and portable electronics where precision, reliability, and minimal standby power are essential.

FAQ

What is the maximum reverse voltage this diode can withstand before breakdown?

The BZX38450-C9V1-Q has a nominal Zener voltage of 9.1 V, with guaranteed breakdown occurring between 8.65 V and 9.56 V at I_Z = 50 µA. Its absolute maximum non-repetitive peak reverse voltage is not specified separately; instead, it is limited by P_ZSM = 40 W for 100 µs pulses, corresponding to ~200 V at 200 mA surge current. Continuous reverse operation above 9.56 V risks thermal runaway unless current is strictly limited.

Can this Zener be used in forward-bias mode as a regular diode?

Yes - the BZX38450-C9V1-Q exhibits a forward voltage ≤ 0.9 V at 10 mA, consistent with standard silicon PN junction behavior. However, its forward characteristics are not characterized beyond that single point, and it is not optimized for rectification. Use in forward conduction is acceptable only for basic clamping or polarity protection where precise VF matching is unnecessary.

How does the ±5 % tolerance affect regulation accuracy in a 3.3 V LDO feedback network?

When used as a shunt reference in an LDO feedback divider, the ±5 % V_Z tolerance directly propagates to output voltage error - e.g., a 9.1 V Zener with ±5 % yields 8.65–9.56 V, translating to ~±1.5 % error in a typical resistor-ratio-based 3.3 V setpoint. For tighter output accuracy, pair with precision resistors or select the ±2 % B-series variant.

Is thermal derating required when mounted on a 2-layer PCB with 1 oz copper?

Yes - the 300 mW rating assumes mounting on single-sided FR4 with tin-plated copper. On a 2-layer board with internal ground plane, thermal resistance improves, but derating remains necessary above 25 °C ambient. At 85 °C ambient, maximum continuous power drops to ~180 mW using R_th(j-a) = 415 K/W, calculated as P_max = (T_j(max) − T_amb) / R_th(j-a) = (150 − 85) / 415 ≈ 0.157 W.