Diodes Incorporated 1SMB5923B-13

Overview

1SMB5923B-13 from Diodes Incorporated is a 3.0W surface-mount power Zener diode with a nominal zener voltage of 8.2V (±5%), 45.7Ω dynamic impedance at 3.5mA test current, and 182mA maximum zener current. It provides precise voltage regulation in DC power rails and overvoltage protection circuits for industrial power supplies and automotive control modules.

For engineers reviewing the 1SMB5923B-13 datasheet, 1SMB5923B-13 pinout, 1SMB5923B-13 application, or 1SMB5923B-13 equivalent, key selection criteria include zener voltage tolerance, thermal resistance (226°C/W), ESD rating (>16kV HBM), SMB package compatibility, and derating behavior above +25°C ambient.

Technical Context

This Zener diode operates in reverse breakdown to maintain stable reference voltage under varying load and temperature conditions. Its 8.2V nominal zener voltage is specified at 3.5mA test current, with dynamic impedance measured at 60Hz AC signal superimposed on DC bias.

The device uses a planar epitaxial construction with copper alloy leadframe and matte tin plating, enabling reliable solderability per MIL-STD-202. Thermal performance is characterized by junction-to-ambient resistance of 226°C/W on FR-4 PCB with Diodes Inc.'s recommended pad layout.

Key Specifications

Pinout & Package

Package: SMB (Surface Mount Small Outline), molded plastic case with UL 94V-0 flammability rating, cathode band polarity marking, and 0.096 g mass.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5923B-TR and BZX84-C8V2, the 1SMB5923B-13 delivers 2× higher power handling than the SOT-23 alternative and full SMT compatibility versus the DO-41 part-making it optimal for production-grade 8.2V shunt regulation in compact, thermally demanding applications.

Availability

1SMB5923B-13 is available at Aetrix Electronics and suitable for industrial power supplies, automotive ECUs, telecom line cards, and medical diagnostic equipment requiring stable component supply and RoHS-compliant sourcing.

Supply support for 1SMB5923B-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, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

This device belongs to the SMB-series power Zener diode product line, engineered for high-reliability voltage regulation and transient suppression in automotive, industrial, and communications infrastructure applications.

FAQ

What is the maximum continuous zener current for 1SMB5923B-13 at +75°C ambient?

The maximum zener current is 182 mA at 25°C ambient, but derating applies above +25°C. At +75°C, power dissipation is limited to 3.0 W, so maximum continuous current is calculated as 3.0 W ÷ 8.2 V ≈ 366 mA - however, the datasheet specifies IZM = 182 mA as the absolute maximum rated current regardless of temperature, based on thermal limits at the junction and terminal interface.

Does 1SMB5923B-13 require external series resistance in shunt regulator configurations?

Yes - a current-limiting resistor must be placed in series with the anode to ensure the diode operates within its 3.0 W power limit and 182 mA IZM rating. The resistor value is determined by (VIN – 8.2 V) / IZ, where IZ is selected between 3.5 mA (minimum regulation current) and 182 mA (maximum safe current), depending on load and stability requirements.

How does the temperature coefficient of zener voltage affect regulation accuracy in wide-temperature applications?

For 1SMB5923B-13 (8.2 V), the typical temperature coefficient is approximately +4.5 mV/°C near room temperature. Over a −40°C to +125°C range, this contributes up to ±0.74 V drift - meaning system-level compensation or tighter initial tolerance (±2.5%) may be needed for sub-1% total regulation accuracy across temperature.

Can 1SMB5923B-13 be used for transient voltage suppression (TVS) in addition to DC regulation?

No - while it can absorb short-duration surges within its 3.0 W rating, it lacks the fast response (<1 ns) and high peak pulse power (kW-level) of dedicated TVS diodes. Its 182 mA IZM and 226°C/W RθJA make it suitable only for low-energy clamping; use SMAJ8.0A or similar for IEC 61000-4-5 surge protection.