Diodes Incorporated 1SMB5924B-13

Overview

1SMB5924B-13 from Diodes Incorporated is a 3.0W surface-mount power Zener diode with nominal zener voltage of 9.1V (±5%), 41.2Ω dynamic impedance at 4mA test current, and 164mA maximum zener current. It provides precise voltage regulation in DC power supply rails, overvoltage protection circuits, and reference voltage generation for industrial power converters.

For engineers reviewing the 1SMB5924B-13 datasheet, 1SMB5924B-13 pinout, 1SMB5924B-13 application, or 1SMB5924B-13 equivalent, key selection criteria include zener voltage tolerance, thermal resistance (226°C/W), ESD rating (>16kV HBM), SMB package footprint compatibility, and derating behavior above +25°C ambient.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain stable voltage across its terminals under varying load and input conditions. Its 9.1V nominal zener voltage is specified at 4mA test current, with low dynamic impedance (41.2Ω) ensuring minimal voltage deviation during transient current changes.

The device uses an SMB plastic package with cathode band polarity marking and achieves 3.0W power dissipation at TL = +75°C, derating linearly at 40mW/°C above that temperature. Thermal resistance from junction to ambient is 226°C/W on FR-4 PCB per AP02001 pad layout.

Key Specifications

Pinout & Package

Package: SMB (Surface Mount Bandolier), molded plastic case with UL 94V-0 flammability rating, cathode band marking, and matte tin-plated copper alloy leadframe. Dimensions: 3.30–3.94mm (L) × 4.06–4.57mm (W) × 1.96–2.21mm (H).

Key Features

Applications

Availability

1SMB5924B-13 is available at Aetrix Electronics and suitable for industrial power supply regulation, automotive body control modules, telecom line card protection, and medical diagnostic equipment requiring stable component supply and RoHS-compliant sourcing.

Supply support for 1SMB5924B-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 centers across Asia and manufacturing in Taiwan and China.

The SMB-series Zener diodes are engineered for high-reliability surface-mount voltage regulation and transient suppression in industrial, automotive, and communications infrastructure applications.

FAQ

What is the maximum continuous power dissipation for 1SMB5924B-13 at +75°C?

The maximum continuous power dissipation is 3.0W at terminal temperature (T_L) = +75°C. Above this temperature, power must be linearly derated at 40mW/°C. At ambient +25°C on standard FR-4 PCB, the rated power drops to 550mW due to higher thermal resistance (226°C/W).

How does the zener voltage change with temperature?

The temperature coefficient of V_Z for 1SMB5924B-13 is approximately +5.5mV/°C near 9.1V, as derived from Figure 2 in DS32125 Rev. 8-2. This positive TC means voltage increases ~0.55V over a 100°C range, requiring compensation in precision reference designs.

Is 1SMB5924B-13 compatible with lead-free reflow profiles?

Yes - it features matte tin plating on copper alloy leadframe and is qualified for lead-free reflow per J-STD-020 Level 1 moisture sensitivity. Peak reflow temperature up to 260°C is supported without degradation, and the device meets IPC/JEDEC J-STD-020D.01 standards.

Can 1SMB5924B-13 replace older 1N5239B Zeners in existing designs?

No - while both regulate near 9.1V, 1SMB5924B-13 has 3.0W power rating and SMB package, whereas 1N5239B is a 0.5W DO-35 device. Direct replacement requires PCB layout revision and thermal validation; electrical substitution is only valid if power and footprint constraints are re-evaluated.