Nexperia USA Inc. BZX384-C18,115

Overview

BZX384-C18,115 from Nexperia is a ±5 % tolerance Zener voltage regulator diode in SOD323 (SC-76) package, rated for 18 V nominal breakdown voltage at 5 mA, 300 mW total power dissipation, and 150 °C maximum junction temperature. It provides stable reference voltage in low-power linear regulation and overvoltage protection circuits for consumer and industrial power supplies.

For engineers reviewing the BZX384-C18,115 datasheet, BZX384-C18,115 pinout, BZX384-C18,115 application, or BZX384-C18,115 equivalent, key selection criteria include Zener voltage tolerance (±5 %), differential resistance (225 Ω max at 5 mA), reverse current (≤0.05 μA at 14.4 V), thermal resistance (415 K/W junction-to-ambient), and non-repetitive peak reverse power capability (40 W).

Technical Context

This device operates as a two-terminal shunt voltage reference, maintaining regulated output by conducting reverse current above its specified Zener voltage. Its 18 V nominal breakdown is defined at I_Z = 5 mA with a temperature coefficient of +12.6 mV/K, indicating positive drift with rising temperature.

The SOD323 package enables surface-mount integration with low thermal resistance to solder point (110 K/W), supporting reliable operation under transient surges up to 40 W for 100 μs pulses while limiting steady-state dissipation to 300 mW at T_amb ≤ 25 °C on FR4 PCB.

Key Specifications

Pinout & Package

The BZX384-C18,115 is housed in a SOD323 (SC-76) plastic surface-mount package with cathode marked by a bar on the body. The device has two terminals: anode (A) and cathode (K), with no internal connections beyond the Zener junction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX384-C18,115, the BZX384-B18,115 offers improved voltage accuracy at higher cost, while MMBZ5246BS,115 trades 100 mW power headroom for potentially lower leakage-making the C-grade optimal for cost-sensitive, moderate-surge industrial regulation.

Availability

BZX384-C18,115 is available at Aetrix Electronics and suitable for low-power voltage reference, overvoltage protection, signal clamping, and microcontroller reset circuits requiring stable component supply and long-term obsolescence management.

Supply support for BZX384-C18,115 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 specializing in high-volume, high-reliability discrete and logic devices, with manufacturing rooted in process innovation and automotive-grade quality systems.

The BZX384 series belongs to Nexperia's precision Zener diode product line, engineered for general-purpose voltage regulation and protection in consumer, industrial, and computing applications where compact size and consistent parametric performance are critical.

FAQ

What is the Zener voltage tolerance and test condition for BZX384-C18,115?

The BZX384-C18,115 has a nominal Zener voltage of 18 V with ±5 % tolerance, verified at I_Z = 5 mA and T_j = 25 °C. The actual working range is 16.8 V to 19.1 V, and the device exhibits a temperature coefficient of +12.6 mV/K, meaning its breakdown voltage increases with junction temperature.

Can BZX384-C18,115 be used in place of a 20 V Zener diode?

No-BZX384-C18,115 is specifically rated for 18 V nominal breakdown (16.8–19.1 V range). Substituting it for a 20 V Zener would result in premature conduction and incorrect regulation. For 20 V, use BZX384-C20,115 (18.8–21.2 V range), which shares identical package, power rating, and thermal characteristics.

What is the maximum reverse current at 14.4 V and why does it matter?

The maximum reverse current is 0.05 μA at V_R = 14.4 V (80 % of nominal V_Z). This low leakage ensures minimal power loss and accurate threshold detection in high-impedance circuits such as reset generators or comparator reference nodes, where even nanoampere currents could shift operating points.

How does the SOD323 package affect thermal performance in continuous operation?

In free air on FR4 PCB, the BZX384-C18,115 has R_th(j-a) = 415 K/W, limiting continuous dissipation to ~300 mW only at T_amb ≤ 25 °C. At 70 °C ambient, derated power drops to ~180 mW. For sustained >200 mW loads, board-level copper pour or adjacent thermal vias are recommended to reduce effective thermal resistance.