Diodes Incorporated SB550-B

Overview

SB550-B from Diodes Incorporated is a 5.0A, 50V Schottky barrier rectifier in DO-201AD package, featuring low forward voltage drop (0.67V @ 5.0A), high surge capability (150A peak), and RoHS-compliant tin-plated leads. It serves as a primary output rectifier in low-voltage DC/DC converters and polarity protection circuits for industrial power supplies.

For engineers reviewing the SB550-B datasheet, SB550-B pinout, SB550-B application, or SB550-B equivalent, key selection criteria include its 50V VRRM rating, 0.67V forward voltage at rated current, thermal resistance of 25°C/W (junction-to-ambient), and DO-201AD mechanical compatibility with high-current PCB layouts.

Technical Context

This Schottky rectifier uses epitaxial construction with guard ring die design to enhance transient protection and reduce reverse recovery losses. Its low forward voltage enables high-efficiency operation in 3.3V–48V output stages where conduction loss dominates thermal design.

The device is rated for continuous 5.0A average forward current under standard mounting conditions (9.5mm lead length), with derating required for capacitive loads (−20% current). Junction temperature range spans −65°C to +125°C, supporting operation in harsh ambient environments.

Key Specifications

Pinout & Package

Package: DO-201AD molded plastic case (UL 94V-0), 1.1 g mass, cathode band polarity marking, bright tin-plated leads solderable per MIL-STD-202 Method 208.

Key Features

Applications

Availability

SB550-B is available at Aetrix Electronics and suitable for AC/DC adapters, motor control boards, solar charge controllers, and industrial PLCs requiring stable component supply with consistent DO-201AD mechanical form factor and bulk packaging.

Supply support for SB550-B 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 Europe.

The SBx50 series belongs to Diodes' high-current Schottky rectifier product line, engineered specifically for efficiency-critical secondary-side rectification in 5–48V power systems where low VFM and surge resilience are mandatory.

FAQ

What is the maximum junction temperature for SB550-B?

The SB550-B has a maximum operating junction temperature of +125°C, validated per JEDEC JESD22-A108. This rating applies under continuous 5.0A forward current with 9.5mm lead length and free-air conditions. Derating is required above 25°C ambient per Figure 1 in DS23024 Rev. 8.

Can SB550-B replace SB540 in an existing design?

Yes, SB550-B is a direct upgrade from SB540 with identical DO-201AD package and pinout, but offers higher 50V VRRM (vs. 40V) and same 0.67V VFM at 5A. No layout change is needed, and the increased blocking voltage improves margin in 36V nominal systems subject to line transients.

Is SB550-B suitable for high-frequency switching applications above 100kHz?

Yes - as a Schottky rectifier with near-zero reverse recovery time, SB550-B performs reliably up to 500kHz in hard-switched topologies. Its low junction capacitance (≈300pF at 4V, per Fig. 5) minimizes switching loss and EMI generation compared to fast-recovery silicon diodes.

Does SB550-B meet automotive qualification standards?

No - SB550-B is not AEC-Q101 qualified. It is rated for industrial temperature range (−65°C to +125°C) and RoHS compliance, but lacks automotive-specific stress testing, lot traceability, and failure rate reporting required for automotive ECUs or ADAS power supplies.