Diodes Incorporated SBM340-13

Overview

SBM340-13 from Diodes Incorporated is a 3A, 40V surface-mount Schottky barrier rectifier in the POWERMITE®3 package, featuring 0.46V typical forward voltage at 3A/25°C, 50A non-repetitive surge rating, and guard ring die construction for transient protection. It is used in low-voltage DC-DC converter freewheeling paths and polarity protection circuits in industrial power supplies.

For engineers reviewing the SBM340-13 datasheet, SBM340-13 pinout, SBM340-13 application, or SBM340-13 equivalent, key selection criteria include forward voltage drop at operating current, thermal resistance (R_θJS = 3.4°C/W), reverse leakage at elevated temperature, and compatibility with high-frequency switching topologies requiring low recovery loss.

Technical Context

This Schottky rectifier uses a guard ring die structure to enhance transient voltage immunity and suppress edge breakdown. Its low V_F (0.46V typ. @ 3A, 25°C) minimizes conduction loss in 5–12V output stages, while its 180pF junction capacitance supports operation up to several MHz in synchronous rectification and flyback snubberless designs.

The device is rated for continuous 3A average forward current with derating above 25°C ambient, and sustains 50A single half-sine surge at 100°C case temperature. Its R_θJS of 3.4°C/W enables direct PCB copper pad heat sinking via Pin 3 (bottom-side thermal tab), critical for compact power layouts.

Key Specifications

Pinout & Package

Package: POWERMITE®3 - molded plastic case (UL 94V-0), 0.072g weight, moisture sensitivity level 1, with bottom-side thermal pad (Pin 3) for enhanced heat dissipation. Pins 1 and 2 must be electrically connected on PCB per datasheet layout guidance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Schottky rectifier applications.

Compared with PDS340-13, SBM340-13 offers identical performance but faces obsolescence risk; versus SS34H-TP, it delivers lower conduction loss and superior thermal coupling-justifying continued use where legacy qualification is maintained.

Availability

SBM340-13 is available at Aetrix Electronics and suitable for industrial power supplies, automotive accessory modules, and embedded DC-DC converter designs requiring stable component supply and known thermal behavior.

Supply support for SBM340-13 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, serving industrial, computing, consumer, and communications markets with high-reliability components.

The POWERMITE®3 Schottky rectifier product line targets space-constrained, thermally demanding power conversion applications where low forward voltage and direct PCB thermal coupling are essential design requirements.

FAQ

Is SBM340-13 still in active production?

No-SBM340-13 is officially obsolete per Diodes Incorporated's DS30362 Rev. 7 documentation. The recommended replacement is PDS340-13, which maintains identical electrical and mechanical specifications with updated date coding and marking. Aetrix Electronics holds limited legacy stock for design continuity and last-time buys.

What is the correct PCB pad layout for thermal performance?

Per Diodes Inc. AP02001, Pin 3 (bottom thermal pad) must be soldered to a ≥100mm² 2oz copper pour with ≥4 thermal vias (0.3mm diameter) connecting to inner or backside ground planes. Pins 1 and 2 require standard SMD pads per POWERMITE®3 outline; both anode and cathode traces must be ≥1.5mm wide for 3A current handling.

Can SBM340-13 replace a standard PN rectifier in a 24V input circuit?

Yes-if the circuit's peak reverse voltage remains ≤40V and operating temperature stays ≤125°C. Its Schottky architecture eliminates reverse recovery loss, improving efficiency and reducing EMI versus PN types like 1N5404. However, its higher reverse leakage (20mA at 100°C) may increase standby power in always-on systems compared to ultra-low-I_R alternatives.

Why does the datasheet specify "Pins 1 & 2 must be electrically connected"?

This requirement ensures low-inductance cathode return path for high-dI/dt freewheeling operation. Connecting Pins 1 and 2 on the PCB creates a parallel current path that reduces effective loop inductance and mitigates voltage spikes during fast turn-off. It is not a functional short but a layout best practice validated in Diodes Inc.'s reference designs for buck converters.