onsemi BZX84C18_D87Z

Overview

BZX84C18_D87Z from ON Semiconductor is a 18 V ±5% Zener diode in SOT-23 package, rated for 250 mW power dissipation at 25°C ambient, with typical zener impedance of 20 Ω at 20 mA and reverse leakage current ≤0.05 µA at 12.6 V, used for voltage regulation and reference in low-power analog circuits.

For engineers reviewing the BZX84C18_D87Z datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, dynamic impedance at specified test current, thermal resistance (R_JA = 465°C/W), junction temperature range (–55°C to +150°C), and SOT-23 footprint compatibility with space-constrained PCB layouts.

Technical Context

The BZX84C18_D87Z operates as a silicon planar epitaxial Zener diode, designed for stable voltage reference and overvoltage clamping in DC bias networks. It exhibits a positive temperature coefficient of +12.4 mV/°C at 5 mA and capacitance of 100 pF at 0 V reverse bias, 1 MHz.

Its electrical behavior is defined under standardized test conditions: zener voltage measured at I_Z = 5.0 mA (16.8–19.1 V), 1.0 mA (16.7–19.0 V), and 20 mA (16.9–19.2 V); forward voltage ≤0.9 V at 10 mA; and maximum repetitive peak working current of 250 mA.

Key Specifications

Pinout & Package

Package: SOT-23 (TO-236AB), surface-mount, 3-terminal plastic case with cathode marked by band. Standard JEDEC MO-215 outline; body dimensions 2.9 mm × 1.3 mm × 1.0 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84C18_D87Z, MMBZ5245B offers higher power handling but shares identical voltage specs and package; BZX84-C18 matches all electrical parameters and adds AEC-Q200 qualification-making it suitable for automotive environments without layout change.

Availability

BZX84C18_D87Z is available at Aetrix Electronics and suitable for voltage reference, overvoltage protection, and bias network applications requiring stable component supply, consistent parametric performance, and long-term obsolescence management.

Supply support for BZX84C18_D87Z 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

ON Semiconductor is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The BZX84 series belongs to ON Semiconductor's general-purpose Zener diode product line, engineered for cost-effective, reliable voltage regulation and clamping in high-volume consumer and industrial electronics.

FAQ

What is the zener voltage tolerance of BZX84C18_D87Z?

The BZX84C18_D87Z has a zener voltage tolerance of ±5%, meaning its nominal 18 V rating spans 16.8 V to 19.1 V at 5 mA test current. This tolerance is confirmed in the Absolute Maximum Ratings table and Electrical Characteristics chart of the official ON Semiconductor datasheet Rev. 1.10. The BZX84C18_D87Z maintains this specification across its full operating temperature range.

What is the maximum power dissipation for BZX84C18_D87Z at room temperature?

The BZX84C18_D87Z is rated for 250 mW power dissipation at T_A = 25°C when mounted on a standard FR-4 PCB (76.2 mm × 114.3 mm). This value is specified in the Absolute Maximum Ratings table and assumes no forced airflow or heatsinking. Derating is required above 25°C ambient per its R_JA = 465°C/W thermal resistance. The BZX84C18_D87Z must not exceed this limit to ensure reliable long-term operation.

Does BZX84C18_D87Z have a specified forward voltage?

Yes, the BZX84C18_D87Z has a maximum forward voltage of 0.9 V at I_F = 10 mA, as stated in the Electrical Characteristics summary. This parameter applies across the entire BZX84 series and is verified under standard test conditions. The forward voltage characteristic is relevant when the device is used in polarity-sensitive protection circuits or during power-up sequencing where anode-cathode conduction may occur. The BZX84C18_D87Z behaves like a standard silicon diode in forward bias.

What is the zener impedance of BZX84C18_D87Z at 20 mA test current?

The BZX84C18_D87Z exhibits a maximum zener impedance of 20 Ω at I_Z = 20 mA, as documented in the Electrical Characteristics table. This low dynamic impedance ensures minimal voltage variation under changing load conditions, making the BZX84C18_D87Z suitable for precision reference applications. The impedance value is measured at 25°C and remains stable across its operational junction temperature range. The BZX84C18_D87Z achieves this performance through optimized silicon doping and planar epitaxial construction.

Is BZX84C18_D87Z compatible with automated SMT assembly?

Yes, the BZX84C18_D87Z uses the industry-standard SOT-23 (TO-236AB) package, fully compatible with automated pick-and-place equipment and reflow soldering profiles per J-STD-020. Its 2.9 mm × 1.3 mm footprint, coplanar leads, and JEDEC-compliant land pattern enable high-yield assembly. The BZX84C18_D87Z is supplied in EIA-481-compliant tape-and-reel packaging for seamless integration into SMT lines. No special tooling or process adjustments are required.