Diodes Incorporated BZX84C18S-7-F

Overview

BZX84C18S-7-F from Diodes Incorporated is a dual 200 mW surface-mount Zener diode in SOT-363 package, rated for 18 V nominal Zener voltage (16.8–19.1 V range at 5 mA), with 45 Ω maximum Zener impedance at test current and 0.1 µA maximum reverse leakage at 12.6 V. It serves as a precision voltage reference or overvoltage clamp in low-power analog signal conditioning circuits.

For engineers reviewing the BZX84C18S-7-F datasheet, BZX84C18S-7-F pinout, BZX84C18S-7-F application, or BZX84C18S-7-F equivalent, key selection criteria include Zener voltage tolerance, dynamic impedance at operating current, thermal resistance (625 °C/W), and SOT-363 footprint compatibility with high-density PCB layouts.

Technical Context

This device integrates two independent Zener diodes in a single ultra-small SOT-363 package, sharing no internal connection-each diode operates as a discrete 18 V regulation element. Its planar die construction ensures stable breakdown characteristics across -65 °C to +150 °C operating temperature range.

The Zener exhibits a positive temperature coefficient of +12.4 to +16.0 mV/°C at 5 mA test current, enabling predictable drift compensation in bias networks. Reverse current remains ≤0.1 µA up to 12.6 V, supporting low-leakage voltage reference designs.

Key Specifications

Pinout & Package

Package: SOT-363 - ultra-small surface-mount plastic case (2.0–2.2 mm × 1.15–1.35 mm × 0.9–1.0 mm height), UL 94V-0 rated, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5245BS-7-F and BZX84C18LT1G, BZX84C18S-7-F uniquely delivers two independent 18 V Zeners in one SOT-363 package-critical for space-constrained dual-reference or differential-clamp designs where isolation and footprint efficiency outweigh raw power or impedance advantages.

Availability

BZX84C18S-7-F is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body electronics, and portable medical instrumentation requiring stable component supply and long-term obsolescence management.

Supply support for BZX84C18S-7-F 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in California, with design, manufacturing, and distribution operations across Asia and the Americas.

This part belongs to the BZX84C series of dual Zener diodes-designed specifically for compact, low-power voltage regulation and protection in high-density consumer, computing, and industrial PCBs.

FAQ

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

The BZX84C18S-7-F has a nominal Zener voltage of 18 V with a guaranteed range of 16.8–19.1 V at 5 mA test current. Its absolute maximum reverse voltage is defined by its breakdown characteristic-not a fixed "withstand" rating. Operation below 12.6 V ensures ≤0.1 µA leakage; sustained reverse bias above 19.1 V risks exceeding 200 mW dissipation unless current is strictly limited.

Can both Zener diodes be used simultaneously in the same circuit without interference?

Yes-pins C1/A1 and C2/A2 form two fully isolated Zener structures inside the SOT-363 package. No internal connection exists between them. Each diode operates independently with identical 18 V characteristics, enabling concurrent use in differential references, dual-rail clamps, or redundant bias networks without crosstalk or shared thermal coupling.

Is this device suitable for use in automotive applications per AEC-Q200?

No-BZX84C18S-7-F is not AEC-Q200 qualified. While it operates from -65 °C to +150 °C and meets RoHS/lead-free requirements, Diodes Incorporated does not list it in their AEC-Q200 stress-tested portfolio. For automotive-grade Zener references, consider the AZ series (e.g., AZBZX84C18S-7-F), which undergoes full qualification testing including temperature cycling and humidity bias.

How does the temperature coefficient affect regulation accuracy over temperature?

The BZX84C18S-7-F exhibits a +12.4 to +16.0 mV/°C temperature coefficient at 5 mA. Over a 100 °C range (e.g., −40 °C to +60 °C), this introduces ±1.24–1.60 V drift in Zener voltage-approximately ±6.9–8.9% of nominal 18 V. For high-accuracy references, this drift must be compensated via circuit design (e.g., TC-matched components) or calibrated out in system firmware.