Diodes Incorporated BZT52C51S-13

Overview

BZT52C51S-13 from Diodes Incorporated is a surface-mount Zener diode with nominal zener voltage 51 V, ±6% tolerance (48.0–54.0 V), 200 mW power dissipation, and 100 Ω zener impedance at 5 mA test current - used for precision voltage regulation and overvoltage protection in low-power analog circuits.

For engineers reviewing the BZT52C51S-13 datasheet, BZT52C51S-13 pinout, BZT52C51S-13 application, or BZT52C51S-13 equivalent, key selection criteria include zener voltage accuracy, thermal resistance (833 °C/W), SOD-323 package footprint compatibility, reverse leakage (0.1 µA @ 38 V), and RoHS-compliant "Green" construction.

Technical Context

This Zener diode operates in reverse breakdown to maintain stable reference voltage under varying load and temperature conditions. Its planar die construction ensures consistent breakdown characteristics and low dynamic impedance (100 Ω @ 5 mA, 1 kHz).

Designed for medium-current regulation up to 5 mA, it features low forward voltage (0.9 V @ 10 mA) and wide operating temperature range (−65 °C to +150 °C), enabling use in industrial sensor signal conditioning and power rail clamping where thermal stability is critical.

Key Specifications

Pinout & Package

Package: SOD-323 - ultra-small plastic surface-mount case (2.40 mm × 1.35 mm × 0.95 mm), moisture sensitivity level 1, matte tin-plated terminals solderable per MIL-STD-202 Method 208.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5251BS-7-F and BZX84-C51, the BZT52C51S-13 offers optimal balance of compact SOD-323 size, industry-standard 200 mW rating, and proven reliability in automated manufacturing - ideal for cost-sensitive, high-volume industrial control modules.

Availability

BZT52C51S-13 is available at Aetrix Electronics and suitable for industrial sensor interfaces, USB port protection circuits, and programmable logic controller I/O modules requiring stable component supply and long-term lifecycle support.

Supply support for BZT52C51S-13 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, specializing in high-reliability, application-optimized components for industrial, computing, and consumer markets.

The BZT52 series belongs to Diodes' general-purpose Zener diode product line, engineered for robust voltage regulation and transient suppression in cost-sensitive, high-volume surface-mount applications.

FAQ

What is the maximum reverse voltage this Zener can withstand before breakdown?

The BZT52C51S-13 has a nominal zener voltage of 51 V with a guaranteed range of 48.0–54.0 V at 5 mA test current. It begins controlled reverse breakdown within this range and maintains regulation up to its 200 mW power limit. At voltages below 48.0 V, reverse leakage remains ≤0.1 µA @ 38 V - no significant conduction occurs until reaching the specified zener threshold.

Can this device be used in series or parallel configurations for higher voltage or current handling?

No - Zener diodes like the BZT52C51S-13 are not designed for parallel operation due to mismatched breakdown voltages causing current hogging. Series connection is possible for higher voltage references but requires matched units and balancing resistors; however, the 200 mW rating and thermal coupling limitations make such configurations impractical without derating and careful thermal design.

Is the SOD-323 package compatible with standard reflow profiles for lead-free assembly?

Yes - the SOD-323 package is rated for moisture sensitivity level 1 per J-STD-020 and supports standard lead-free reflow profiles (peak 260 °C). Its matte tin annealed terminals meet MIL-STD-202 Method 208 solderability requirements, and the "Green" molding compound is qualified for Pb-free processes without delamination or popcorning risk.

How does the 833 °C/W thermal resistance impact real-world PCB layout?

A thermal resistance of 833 °C/W means that at full 200 mW dissipation, the junction temperature rises ~167 °C above ambient - exceeding safe limits. Therefore, practical designs must limit average power to ≤60 mW (or use copper pour heatsinking) to keep T_J ≤125 °C. The SOD-323 pad layout (2.40 mm × 1.35 mm) should include ≥10 mm² of 1-oz copper connected to each terminal to reduce effective R_θJA.