www.irf.com

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IRPLCFL5U

International Rectifier

• 233 Kansas Street, El Segundo, CA 90245

USA

!

CFL Ballast for 26W/Spiral Lamp, 120VAC Input

By Cecilia Contenti

TOPICS COVERED

Overview

Functional Description

Features

Fault Conditions

Electrical Characteristics

RPLCFL5U Layout

IR2520D Ballast Control IC

Design Procedure to adapt the

Circuit Description

design to different lamp types

1. Overview

The IRPLCFL5U reference design is an electronic ballast for driving 26W compact fluorescent

lamps from 120VAC. The circuit provides all of the necessary functions for preheat, ignition and on-

state operation of the lamp and also includes the EMI filter and the rectification stage. The circuit is

built around the IR2520D Ballast Control IC. The IR2520D provides adjustable preheat time, adjust-

able run frequency to set the lamp power, high starting frequency for soft start and to avoid lamp

flash, fault protection for open filament condition and failure to strike, low AC line protection and

auto-restart after line brownout conditions. The IR2520D is a low-cost solution specific for CFL

applications. The IR2520D has only 8 pins and allows the component count for the complete ballast

to be reduced down to 20 components.

2. Features

Programmable run frequency

Programmable preheat time

Open filaments and no-lamp protection

Failure to Strike and deactivated-lamp protection

Low AC line protection