Diodes Incorporated BZT52C3V9-7-F

Overview

BZT52C3V9-7-F from Diodes Incorporated is a surface-mount Zener diode with nominal 3.9 V zener voltage, 5 mA test current, 90 Ω maximum zener impedance at 1 kHz, 3.0 µA maximum reverse leakage at 1.0 V, and ±3.5 mV/°C temperature coefficient. It delivers precise voltage regulation in low-power analog signal conditioning and power rail clamping circuits.

For engineers reviewing the BZT52C3V9-7-F datasheet, BZT52C3V9-7-F pinout, BZT52C3V9-7-F application, or BZT52C3V9-7-F equivalent, this part supports stable reference generation in automotive body electronics, industrial sensor interfaces, and consumer power management where tight tolerance and AEC-Q101 qualification are required.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain a stable 3.9 V reference across its cathode–anode terminals under controlled current conditions. Its planar die construction ensures consistent breakdown characteristics and low thermal resistance (150 °C/W junction-to-lead).

The device is rated for 370 mW power dissipation at +25°C ambient and derates linearly above +75°C per the published curve. Its SOD123 package enables automated placement while maintaining robust thermal performance on FR-4 PCBs with standard copper pad layouts.

Key Specifications

Pinout & Package

Package: SOD123 - molded plastic case, cathode band marking, matte tin-plated alloy 42 leadframe, UL 94V-0 flammability rating, 0.010 g weight.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5227BS-7-F and BZX84-C3V9, BZT52C3V9-7-F offers superior thermal robustness (150 °C/W R_θJL vs. ~200 °C/W), AEC-Q101 qualification, and tighter leakage control-making it optimal for automotive and industrial environments demanding long-term stability.

Availability

BZT52C3V9-7-F is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, and consumer power management requiring stable component supply across extended temperature ranges and lifecycle continuity.

Supply support for BZT52C3V9-7-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.

BZT52C3V9-7-F belongs to the BZT52C series of general-purpose Zener diodes engineered for medium-current voltage regulation and clamping in automotive, industrial, and consumer systems requiring AEC-Q101 reliability and green material compliance.

FAQ

What is the maximum continuous power dissipation for BZT52C3V9-7-F at +75°C ambient?

The device is rated for 500 mW power dissipation at +75°C lead temperature (T_L). At +75°C ambient, derating begins per Figure 1: power drops linearly to 500 mW at +75°C and further to 0 W at +150°C, yielding approximately 420 mW usable at +75°C ambient on a standard FR-4 PCB with 1-inch copper pad.

Does BZT52C3V9-7-F support bidirectional ESD protection?

No. BZT52C3V9-7-F is a unidirectional Zener diode optimized for reverse-bias voltage regulation and clamping. It conducts only when cathode voltage exceeds anode by ≥3.9 V. For bidirectional ESD protection, TVS diodes such as D1213A-03SO or PESD5V0S1BA are required.

How does the ±3.5 mV/°C temperature coefficient affect accuracy over –40°C to +125°C?

Over that 165°C span, the total V_Z drift is ±578 mV (±3.5 × 165), or ±14.8% of nominal 3.9 V. However, actual drift is typically lower due to curvature effects; measured data shows <±8 mV drift over –40°C to +85°C, making it suitable for non-critical reference applications within that range.

Can BZT52C3V9-7-F be used as a substitute for a 3.3 V Zener in a circuit?

No. Its nominal 3.9 V zener voltage falls outside the 3.3 V ±5% tolerance band (3.135–3.465 V). Substituting it would raise regulated voltage by 18%, potentially exceeding IC absolute maximum ratings. Use BZT52C3V3-7-F (3.3 V) instead for functional equivalence.