RT8479C Datasheet, PDF (1/15 Pages) Richtek Technology Corporation – Two-Stage Hysteretic LED Driver

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RT8479C
Two-Stage Hysteretic LED Driver with Internal MOSFETs
General Description
The RT8479C is a two-stage controller with dual
MOSFETs and consists of a Boost converter (first stage)
and a Buck converter (second stage). The advantage of
two-stage topology is highly compatible with ET (Electronic
Transformer) and extremely high Power Factor
performance in MR16 / AR111 lighting market fields
applications.
The first stage is a Boost converter for constant voltage
output with inductor peak current over-current protection.
The second stage is a Buck converter for constant output
current by typical constant peak current regulation.
The RT8479C is equipped with dual output gate drivers
for internal power MOSFETs.
The RT8479C is available in the SOP-8 (Exposed Pad)
package.
Applications
 MR16 Lighting
 Signage and Decorative LED Lighting
 Architectural Lighting
 High Power LED Lighting
 Low Voltage Industrial Lighting
 Indicator and Emergency Lighting
 Automotive LED Lighting
Features
 Two-Stage Topology (Boost + Buck)
 Dual MOSFETs Inside
 Wide Input Voltage Range : 4.5V to 36V
 Excellent Power Factor
 Programmable Boost Output Voltage
 Independent Dual Stage Function
 Programmable LED Current with ±5% LED Current
Accuracy
 Input Under-Voltage Lockout Detection
 Thermal Shutdown Protection
Ordering Information
RT8479C
Package Type
SP : SOP-8 (Exposed Pad-Option 2)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
Richtek products are :
 RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
 Suitable for use in SnPb or Pb-free soldering processes.
Simplified Application Circuit
L1 D5
VL
AC 12V
VN
D1 D2
C_IN
D3 D4
R1
R2
C1
To
Dimming
RT8479C
OVP
VCC
ISN
LX1
CREG
VCOMP
ACTL
LX2
GND
VCC
C_OUT
R_SENSE
LED+
D6
C3
C2
LED-
L2
Copyright ©2014 Richtek Technology Corporation. All rights reserved.
DS8479C-04 August 2014
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
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