Diodes Incorporated BZT52C33SQ-7-F

Overview

BZT52C33SQ-7-F from Diodes Incorporated is a surface-mount Zener diode with nominal 33 V zener voltage (31.0–35.0 V range at 2 mA), 200 mW power dissipation, and SOD323 package. It provides precise voltage regulation in low-power biasing, overvoltage protection, and reference circuits for automotive and industrial control modules.

For engineers reviewing the BZT52C33SQ-7-F datasheet, BZT52C33SQ-7-F pinout, BZT52C33SQ-7-F application, or BZT52C33SQ-7-F equivalent, key selection criteria include zener voltage tolerance (±3.0%), maximum zener impedance (325 Ω at 0.5 mA), temperature coefficient (+23.1 to +27.4 mV/°C), reverse leakage (<0.1 µA at 27.4 V), and AEC-Q101 qualification.

Technical Context

This Zener diode operates in reverse breakdown mode with a specified test current of 2 mA, delivering stable voltage regulation under low-current conditions. Its planar die construction and SOD323 package support high-reliability automated assembly in space-constrained PCB layouts.

The device exhibits a positive temperature coefficient (+23.1 to +27.4 mV/°C) and maintains <0.1 µA reverse leakage at VR = 27.4 V. Thermal resistance is 625 °C/W (junction-to-ambient), requiring derating above +25°C per the published power derating curve.

Key Specifications

Pinout & Package

SOD323 package: 2-terminal surface-mount device with cathode band marking; terminals are anode and cathode; no internal connections beyond the two leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5265BS-7-F and BZX84-C33-7-F, BZT52C33SQ-7-F offers tighter voltage tolerance (±3.0% vs. ±5%), AEC-Q101 compliance, and smaller SOD323 footprint-making it optimal for space-constrained, high-reliability automotive and industrial systems where precision and qualification are mandatory.

Availability

BZT52C33SQ-7-F is available at Aetrix Electronics and suitable for automotive ECU power supervision, industrial sensor signal conditioning, and telecom line interface protection requiring stable component supply and AEC-Q101 assurance.

Supply support for BZT52C33SQ-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' automotive-qualified Zener diode product line, engineered specifically for precision voltage reference and overvoltage protection in harsh-environment control systems.

FAQ

What is the maximum reverse leakage current for BZT52C33SQ-7-F at 27.4 V?

The maximum reverse leakage current is 0.1 µA at VR = 27.4 V and TA = +25°C, as specified in the Electrical Characteristics table. This value remains valid across the full operating temperature range (–65°C to +150°C), with leakage increasing only marginally up to 1.0 µA at +125°C per typical characterization data.

Is BZT52C33SQ-7-F suitable for use in high-humidity environments?

Yes. The SOD323 package has a moisture sensitivity level (MSL) of 1 per J-STD-020, meaning it is not humidity-sensitive and does not require dry-packaging or baking prior to assembly. Its molded plastic case meets UL 94V-0 flammability rating and is qualified for automotive under AEC-Q101, including biased HAST testing.

How does the temperature coefficient affect regulation accuracy over –40°C to +125°C?

The temperature coefficient is +23.1 to +27.4 mV/°C. Over a 165°C span, this results in a maximum voltage shift of ~4.5 V (27.4 mV/°C × 165°C), meaning VZ may range from ~28.5 V to ~37.5 V. For precision references, this must be compensated in system-level calibration or combined with temperature-sensing circuitry.

Can BZT52C33SQ-7-F replace a through-hole 1N5256B Zener diode?

No. While both regulate at ~33 V, the BZT52C33SQ-7-F is a surface-mount SOD323 device rated for 200 mW, whereas the 1N5256B is through-hole DO-35 rated for 500 mW. Direct replacement requires verifying thermal design, PCB layout compatibility, and whether the lower power rating meets the application's worst-case dissipation requirements.