Diodes Incorporated SK34-7-F

Overview

SK34-7-F from Diodes Incorporated is a surface-mount Schottky barrier rectifier rated for 40 V maximum recurrent peak reverse voltage, 3.0 A average forward current, and 0.50 V forward voltage at 3.0 A, used in DC/DC converter output stages and low-voltage power supplies where low conduction loss and fast switching are required.

For engineers reviewing the SK34-7-F datasheet, SK34-7-F pinout, SK34-7-F application, or SK34-7-F equivalent, key selection criteria include VF vs. temperature stability, IFSM surge capability under 8.3 ms half-sine conditions, thermal resistance (RθJL = 10 °C/W), and compatibility with 8.0 mm² copper land pads per JEDEC mounting guidelines.

Technical Context

This Schottky rectifier employs guard ring construction to enhance transient voltage immunity and prevent edge breakdown under repetitive reverse-biased stress. Its low forward voltage drop and fast recovery (no minority carrier storage) enable high-efficiency operation in high-frequency switching topologies up to several hundred kHz.

The device operates across –65 °C to +150 °C junction temperature range and exhibits typical junction capacitance of 300 pF at 1 MHz and 4.0 V reverse bias - a value critical for EMI filtering and snubber design in flyback and buck converters.

Key Specifications

Pinout & Package

Package: SMC (DO-214AB), molded plastic case with matte tin lead-free plating, cathode indicated by band, moisture sensitivity level 1 per J-STD-020A.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SK34-7-F, B340A-13-F offers space savings at the cost of reduced surge robustness and thermal performance, while SS34H trades slightly higher VF and leakage for SMA compatibility - both require revalidation of thermal layout and surge margin.

Availability

SK34-7-F is available at Aetrix Electronics and suitable for AC/DC adapters, buck converter auxiliary rectification, USB-C PD input protection, and industrial sensor node power supplies requiring stable component supply and long-term manufacturability.

Supply support for SK34-7-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 analog ICs, specializing in power management, signal integrity, and protection devices for industrial, computing, and consumer markets.

The SKxx series targets cost-sensitive, high-volume power conversion applications where low VF, robust surge rating, and JEDEC-compliant SMC packaging are prioritized over ultra-low leakage or extended temperature grades.

FAQ

Is SK34-7-F suitable for synchronous rectification replacement in a 500 kHz buck converter?

No - SK34-7-F is a passive Schottky rectifier, not a synchronous rectifier IC. It replaces the freewheeling diode in non-synchronous buck designs. For synchronous rectification, a dedicated gate driver + MOSFET or integrated SR controller (e.g., AP3410) is required. This part's zero Qrr and fast turn-off make it ideal as a diode substitute in such topologies.

What is the minimum recommended PCB copper area for thermal management?

Diodes Incorporated specifies an 8.0 mm² (e.g., 2.0 mm × 4.0 mm) copper land pad per terminal for the derating curve in Figure 1. Using less area increases RθJA and reduces allowable I(AV); doubling the pad size to 16 mm² improves thermal performance by ~20%, but does not change RθJL (junction-to-lead), which remains fixed at 10 °C/W.

Does SK34-7-F meet RoHS and REACH requirements?

Yes - the "-F" suffix denotes lead-free matte tin plating, compliant with RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006. The SMC package uses UL 94V-0 rated molding compound, and full compliance documentation is available in Diodes Incorporated's material declarations portal under PN SK34-7-F.

Why is SK34-7-F marked "NOT RECOMMENDED FOR NEW DESIGN"?

Diodes Incorporated recommends migrating to the B3X0 series (e.g., B340B-13-F) due to improved thermal performance (RθJL = 8.5 °C/W), tighter VF distribution, and enhanced surge robustness (IFSM = 120 A). SK34-7-F remains fully qualified and supported for legacy production and repair, but new designs should evaluate B3X0 for better long-term supply and performance headroom.