Diodes Incorporated BZT52C18S-7-F

Overview

BZT52C18S-7-F 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, 45 Ω zener impedance at test current, and SOD323 package. It provides precision voltage regulation in low-power biasing, reference, and overvoltage protection circuits for industrial sensors and automotive ECUs.

For engineers reviewing the BZT52C18S-7-F datasheet, BZT52C18S-7-F pinout, BZT52C18S-7-F application, or BZT52C18S-7-F equivalent, key selection criteria include zener voltage tolerance (±6.1%), temperature coefficient (+12.6 mV/°C), reverse leakage (<0.1 µA at 12.4 V), and SOD323 thermal resistance (625 °C/W).

Technical Context

This Zener diode operates in reverse breakdown mode with a specified test current of 5 mA and exhibits a positive temperature coefficient of +12.6 mV/°C - indicating increasing zener voltage with rising junction temperature. Its 45 Ω dynamic impedance at I_ZT ensures stable regulation under moderate load variation.

The device uses planar die construction in a molded plastic SOD323 case rated UL 94V-0, with matte tin-plated alloy 42 leads and cathode band polarity marking. It is qualified to AEC-Q101 for automotive reliability and rated for operation from −65 °C to +150 °C.

Key Specifications

Pinout & Package

SOD323 is a two-terminal surface-mount package with cathode marked by a visible band on the top surface. The device has no internal circuitry beyond the PN junction; terminals are unidirectional anode/cathode.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMSZ5245B-TP and BZX384-C18, BZT52C18S-7-F offers optimal balance of automotive qualification, compact SOD323 size, and predictable +12.6 mV/°C TC for mid-range current reference use - making it ideal for cost-sensitive, space-limited industrial and automotive modules.

Availability

BZT52C18S-7-F is available at Aetrix Electronics and suitable for industrial sensor signal conditioning, automotive ECU power-rail clamping, and low-power battery monitor reference applications requiring stable component supply and AEC-Q101 compliance.

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

The BZT52C series belongs to Diodes' broad portfolio of surface-mount Zener diodes engineered specifically for precision voltage regulation and transient suppression in automotive, industrial, and consumer electronics - emphasizing AEC-Q101 reliability, tight parametric control, and RoHS-compliant packaging.

FAQ

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

The datasheet specifies that reverse leakage I_R is ≤0.1 µA at V_R = 12.4 V. This value is measured under standard conditions (T_A = 25 °C) and reflects the voltage level below which the diode maintains ultra-low standby current - critical for battery-powered reference designs.

Does BZT52C18S-7-F support reflow soldering per JEDEC J-STD-020?

Yes. The device is rated Moisture Sensitivity Level 1 (MSL-1) per J-STD-020, meaning it can be exposed indefinitely to ambient conditions before reflow and withstands standard Pb-free reflow profiles without preconditioning. Its matte tin finish ensures reliable wetting during soldering.

How does the +12.6 mV/°C temperature coefficient affect long-term voltage reference stability?

This positive TC means V_Z increases by 12.6 mV per °C rise in junction temperature. Over a 100 °C range (−40 to +60 °C ambient, assuming typical self-heating), V_Z shifts ~1.26 V - requiring compensation in high-accuracy references, but acceptable for general-purpose clamping and biasing.

Can BZT52C18S-7-F replace BZT52C18-7-F in existing designs?

Yes. The "S" suffix denotes the SOD323 package variant; BZT52C18-7-F (without "S") is not a valid Diodes part number. All official ordering codes for this series include the "S", confirming BZT52C18S-7-F is the correct and only commercial SOD323 version of the 18 V device.