Diodes Incorporated BZT52C18S-7

Overview

BZT52C18S-7 from Diodes Incorporated is a surface-mount Zener diode with nominal 18 V zener voltage (16.8–19.1 V range at 5 mA), 200 mW power dissipation, and SOD323 package. It provides precise voltage regulation in low-power biasing, reference, and overvoltage protection circuits for automotive ECUs, industrial sensors, and consumer power supplies.

For engineers reviewing the BZT52C18S-7 datasheet, BZT52C18S-7 pinout, BZT52C18S-7 application, or BZT52C18S-7 equivalent, key selection criteria include zener voltage tolerance (±6.3%), dynamic impedance (45 Ω at 5 mA), temperature coefficient (+12.6 mV/°C), and AEC-Q101 qualification for automotive reliability.

Technical Context

This Zener diode operates in reverse breakdown to maintain stable voltage across its terminals under varying current conditions. Its planar die construction ensures consistent breakdown characteristics, while the SOD323 package supports high-density PCB layouts and automated reflow assembly.

The device exhibits a positive temperature coefficient of +12.6 mV/°C above 6 V, enabling predictable drift compensation in reference designs. With 0.1 µA maximum reverse leakage at 12.4 V and 200 mW derated power handling up to +125°C ambient, it suits precision analog and automotive-grade voltage clamping applications.

Key Specifications

Pinout & Package

SOD323 package: 2-terminal surface-mount case with cathode band marking; molded plastic body (UL 94V-0), matte tin-plated alloy 42 leadframe, 0.0049 g weight.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMSZ5245B-7-F and BZX384-C18, BZT52C18S-7 offers tighter integration into automotive PCBs via SOD323 and guaranteed reliability under AEC-Q101 stress tests-critical where field failure risk must be minimized despite slightly wider V_Z tolerance.

Availability

BZT52C18S-7 is available at Aetrix Electronics and suitable for automotive body control modules, industrial 4–20 mA transmitters, and consumer AC/DC adapter feedback circuits requiring stable component supply and long-term lifecycle support.

Supply support for BZT52C18S-7 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 Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

The BZT52C series belongs to Diodes' automotive-qualified Zener diode product line, engineered specifically for robust voltage reference and transient suppression in harsh-environment electronics such as engine control units and ADAS subsystems.

FAQ

What is the maximum reverse voltage (V_R) at which leakage remains ≤0.1 µA?

The BZT52C18S-7 guarantees ≤0.1 µA reverse leakage at V_R = 12.4 V, per the Electrical Characteristics table. This value is specified at T_A = 25°C and serves as the maximum recommended reverse bias for ultra-low-leakage operation-exceeding this voltage increases leakage exponentially near the zener knee.

Can BZT52C18S-7 replace BZT52C15S-7 in a 15 V reference circuit?

No-BZT52C18S-7 has a nominal 18 V zener voltage (16.8–19.1 V range), making it unsuitable as a direct replacement for the 15 V BZT52C15S-7 (13.8–15.6 V). Substituting would raise the regulated voltage by ~3 V, potentially damaging downstream 15 V-tolerant ICs or violating system-level voltage margin requirements.

Is thermal resistance (R_θJA) provided for the SOD323 package?

Yes-the datasheet specifies R_θJA = 625°C/W for the BZT52C18S-7 mounted on an FR-4 PCB with Diodes Incorporated's recommended pad layout. This value assumes standard 1 oz copper, no thermal vias, and natural convection cooling; actual performance improves with enhanced copper area or thermal relief design.

Does the "-7" suffix indicate tape-and-reel packaging?

Yes-the "-7" suffix denotes 3,000-unit tape-and-reel packaging per the Ordering Information table. This format is optimized for automated pick-and-place assembly and complies with EIA-481 standards; the full orderable part number is BZT52C18S-7-F, where "-F" confirms lead-free and RoHS compliance.