Diodes Incorporated BZT52C51-7-F

Overview

BZT52C51-7-F from Diodes Incorporated is a surface-mount 51 V Zener diode in SOD123 package, rated for 500 mW power dissipation at TL = +75°C and 370 mW at TA = +25°C, with ±5% zener voltage tolerance (48.0–54.0 V), 100 Ω maximum zener impedance at 5 mA, and 0.1 µA maximum reverse leakage at 38.0 V. It serves as a precision voltage reference or overvoltage clamp in low-power DC regulation circuits.

For engineers reviewing the BZT52C51-7-F datasheet, BZT52C51-7-F pinout, BZT52C51-7-F application, or BZT52C51-7-F equivalent, key selection criteria include its 51 V nominal breakdown voltage, thermal resistance (RθJA = 338 °C/W), AEC-Q101 qualification, RoHS-compliant green construction, and SOD123 footprint compatibility with automated assembly.

Technical Context

This Zener diode operates in reverse-biased breakdown mode to maintain stable voltage across load variations and temperature shifts. Its planar die construction ensures consistent breakdown characteristics and long-term stability under repetitive surge conditions.

Designed for medium-current general-purpose regulation, it delivers 51 V reference accuracy within ±5% at 5 mA test current, with a negative temperature coefficient of −2.7 mV/°C and total capacitance of ~10 pF at 1 V reverse bias - suitable for noise-sensitive analog monitoring paths.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5257B-7-F and 1N5257B-TAP, BZT52C51-7-F uniquely combines AEC-Q101 qualification, SOD123 manufacturability, and full 370 mW ambient-rated dissipation - making it optimal for automotive and high-reliability SMT production where thermal performance and process compatibility are critical.

Availability

BZT52C51-7-F is available at Aetrix Electronics and suitable for industrial sensor signal conditioning, automotive ECU power rail clamp, and IoT node battery monitor reference requiring stable component supply, traceable lot control, and long-term lifecycle support.

Supply support for BZT52C51-7-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 integrated circuits, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

The BZT52 series belongs to Diodes' general-purpose Zener diode product line, engineered for cost-effective, high-volume voltage regulation and transient suppression in commercial and automotive applications - emphasizing AEC-Q101 reliability, green compliance, and SMT process robustness.

FAQ

What is the maximum steady-state power dissipation for BZT52C51-7-F at +75°C ambient?

The device is rated for 500 mW power dissipation at TL = +75°C (lead temperature), not ambient. At TA = +25°C, the derated limit is 370 mW. Derating follows the curve in Figure 1: linear reduction to zero at +150°C ambient, with slope −3.7 mW/°C above +25°C.

Is BZT52C51-7-F suitable for use in automotive applications?

Yes - it is explicitly qualified to AEC-Q101 standards for high-reliability automotive use, including under-hood and body electronics. The "-7-F" suffix denotes commercial-grade SOD123 packaging; automotive-grade variants carry "Q-7-F" suffix and undergo additional stress testing.

How does the −2.7 mV/°C temperature coefficient affect circuit performance?

This negative coefficient means V_Z decreases by 2.7 mV per degree Celsius rise. In precision references, this drift must be compensated - e.g., by pairing with a positive-TC component or using it in temperature-stable environments (0–50°C). It is not suitable as a standalone high-accuracy reference above 60°C.

Can BZT52C51-7-F replace a 1N5257B in existing designs?

Electrically, yes - both have 51 V nominal V_Z and similar I_ZK/I_ZT specs. However, BZT52C51-7-F uses SOD123 (2.65 × 1.55 mm) vs. DO-35 (4.5 × 2.0 mm), requiring PCB footprint redesign. Thermal performance also differs: R_θJA is 338 °C/W vs. ~500 °C/W for 1N5257B.