Cirrus Logic CRD1680-7W - Manual (Page 3)

CRD1680-7W
DS1017RD3 3
1. INTRODUCTION
The CS1680 is a cascade boost-buck dimmable LED controller IC. The CS1680 uses a Cirrus Logic proprietary in-
telligent digital control that provides exceptional single-lamp and multi-lamp transformer compatibility for non-
dimmer systems and dimmer systems paired with electronic and magnetic low-voltage transformers. The CS1680
integrates a continuous conduction mode (CCM) boost converter that provides transformer compatibility and dimmer
compatibility with a constant output current buck stage. An adaptive digital algorithm controls the boost stage and
dimmer compatibility operation mode to enable flicker-free operation down to 5% output current with leading-edge
and trailing-edge dimmers. For in-depth implementation of the CS1680, please consult documents in Further Read-
ing on page 3 for IC and reference design details.
The CRD1680-7W 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, overcur-
rent detection, boost overvoltage, and overtemperature thermistors protect the system during abnormal conditions.
Details of these features are provided in the CS1680 Dimmable LED Driver IC for Low-voltage Lighting data sheet.
The CRD1680-7W board demonstrates the performance of the CS1680. This reference board has been designed
for an output load of 4
 LEDs in series at a target output current of 430mA (12.0V 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 CS1680 dimmable LED
controller IC.
Extreme caution needs to be exercised while handling this board. This board is to be used by trained professionals
only.
Further Reading
• Cirrus Logic, 2014. “Dimmable LED Driver IC for Low-voltage Lighting,” DS1055F1, AUG 2014.
• Cirrus Logic, 2014. “Design Guide for a CS1680 Dimmable LED Driver IC for Low-voltage Lighting,”
AN379REV3, AUG 2014.
NOTE
If any other Cirrus Logic document contains information conflicting with the device data sheet,
the device data sheet is considered to have the most current and correct data.