Diodes Incorporated SBL4040PT

Overview

SBL4040PT from Diodes Incorporated is a 40A, 40V Schottky barrier rectifier in TO-3P package, featuring low forward voltage drop (0.58 V @ 20 A, 25°C), high surge capability (375 A, 8.3 ms), and thermal resistance of 1.4°C/W. It is designed for low-voltage, high-frequency inverters, freewheeling diode applications, and polarity protection circuits in industrial power supplies.

For engineers reviewing the SBL4040PT datasheet, SBL4040PT pinout, SBL4040PT application, or SBL4040PT equivalent, key selection considerations include its 40V blocking rating, 40A average output current at TC = 100°C, 375A non-repetitive surge rating, low VF performance, and TO-3P thermal mechanical interface for heatsink mounting.

Technical Context

The SBL4040PT uses a Schottky barrier chip with guard ring die construction to enhance transient robustness and reduce leakage under reverse bias. Its low forward voltage minimizes conduction loss in high-current DC/DC and inverter outputs, while the TO-3P package enables direct heatsink attachment for sustained 40A operation at elevated case temperatures.

Rated for 40V DC blocking and 28V RMS reverse voltage, it supports single-phase, half-wave rectification with resistive or inductive loads. Capacitive load derating (−20% current) applies, and typical junction-to-case thermal resistance is 1.4°C/W when mounted on a heatsink per JEDEC standards.

Key Specifications

Pinout & Package

TO-3P package: isolated metal tab (cathode), three leads - anode (center), cathode (tab + outer lead), with molded plastic body rated UL 94V-0. Mounting via tab ensures low thermal impedance to heatsink.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VS-40CPH04 and MBR4040CT, the SBL4040PT offers superior thermal interface via TO-3P tab mounting and tighter VF tolerance, making it optimal for space-constrained, heatsink-integrated industrial rectifier designs where single-device simplicity and thermal predictability are critical.

Availability

SBL4040PT is available at Aetrix Electronics and suitable for industrial DC power supplies, motor drive freewheeling, and telecom rectifier modules requiring stable component supply despite its obsolete status - we maintain legacy inventory with full traceability and documentation.

Supply support for SBL4040PT 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-efficiency power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The SBL40xxPT series belongs to Diodes' high-current Schottky rectifier product line, engineered specifically for low-VF, high-surge industrial power conversion where thermal robustness and reliability under transient stress are mandatory.

FAQ

Is SBL4040PT still in active production?

No - Diodes Incorporated discontinued the SBL4040PT in July 2015, as confirmed in DS30236 Rev. 4. It is marked "OBSOLETE – PART DISCONTINUED" in official documentation. Aetrix Electronics supplies remaining legacy stock with full traceability and RoHS compliance verification per original spec.

What is the maximum allowable case temperature for continuous 40A operation?

The datasheet specifies IO = 40 A at TC = 100°C. Operation beyond this requires derating per Figure 1: at TC = 110°C, IO drops to ~35 A; at TC = 125°C, IO falls to ~28 A. Heatsink design must ensure TC ≤ 100°C under worst-case ambient and airflow conditions.

Can SBL4040PT replace a standard silicon rectifier in a 48V power supply?

Yes - with caveats. Its 40V VRRM provides limited margin above 48V systems; use only where peak reverse voltage stays ≤ 40V (e.g., secondary-side 36V output). Its low VF reduces losses, but ensure layout accommodates TO-3P mounting and cathode isolation.

Does SBL4040PT require a thermal pad or insulator when mounted to a heatsink?

Yes - the metal tab is the cathode terminal and must be electrically isolated from the heatsink unless the system design intentionally references the cathode to chassis ground. Use UL 94V-0 compliant mica or ceramic washers with thermal grease to maintain both electrical safety and thermal performance.