Cirrus Logic CRD1615-8W - Manual (Page 3)

CRD1615-8W
DS1002RD3 3
1. INTRODUCTION
The CS1615 is a 120VAC quasi-resonant flyback mode dimmable LED controller IC. The CS1615 uses a digital con-
trol algorithm that is optimized for high efficiency and >0.9 power factor over an input voltage range (108VAC to
132VAC). The CS1615 integrates a dimmer compatibility circuit with a constant output current, quasi-resonant fly-
back stage. An adaptive dimmer compatibility algorithm controls the dimmer compatibility operation mode to enable
flicker-free operation from 0% to 100% output current with leading-edge, trailing-edge, and digital dimmers.
The CRD1615-8W board is optimized to deliver low system cost in a high-efficiency, flicker-free, phase-dimmable,
solid-state lighting (SSL) solution for incandescent lamp replacement applications. The feedback loop is closed
through an integrated digital control system within the IC. Protection algorithms such as output open/short,
current-sense resistor open/short, and overtemperature thermistors protect the system during abnormal conditions.
When using the CS1615 for a design that does not require active clamp circuitry, the CLAMP pin should be left
floating. Details of these features are provided in the CS1615/16 data sheet DS961 Single Stage Dimmable Offline
AC/DC Controller for LED Lamps.
The CRD1615-8W board demonstrates the performance of the CS1615. This reference board has been designed
for an output load of 10

LEDs in series at 250mA (

28.0V typical).
This document provides the schematic for the board. It includes oscilloscope screen shots that indicate various op-
erating waveforms. Graphs are also provided that document the performance of the board in terms of Efficiency vs.
Line Voltage, Output Current vs. Line Voltage, and Output Current vs. Dim Angle for the CS1615 dimmable LED
controller IC.
Extreme caution needs to be exercised while handling this board. This board is to be used by trained professionals
only.