RT8474A Datasheet, PDF (1/13 Pages) Richtek Technology Corporation – High Voltage Multiple-Topology LED Driver

®
RT8474A
High Voltage Multiple-Topology LED Driver
with Open Detection
General Description
The RT8474A is a current-mode LED driver supporting wide
input voltage range from 4.5V to 50V in multiple topologies.
With the internal 500kHz operating frequency, the size of
the external PWM inductor and input/output capacitors
can be minimized. High efficiency is achieved by a 100mV
current sensing control. LED dimming control can be done
from either analog or PWM signal. The RT8474A provides
an internal soft-start function to avoid inrush current and
thermal shutdown to prevent the device from overheat.
The RT8474A is available in the SOP-8 (Exposed pad)
package.
Features
 High Voltage : V_IN Up to 50V, V_OUT Up to 50V
 Support Multiple-Topologies (Buck / Boost / Buck-
Boost)
 Built-In 2A Power Switch
 Current-Mode PWM Control
 500kHz Fixed Switching Frequency
 Analog or PWM Control Signal for LED Dimming
 Internal Soft-Start to Avoid Inrush Current
 OVP Pin for Adjustable OVP Level Protection (for
Buck Only)
 Under-Voltage Lockout
 Thermal Shutdown
 RoHS Compliant and Halogen Free
Ordering Information
RT8474A
Package Type
SP : SOP-8 (Exposed-Option 2)
Note :
Lead Plating System
G : Green (Halogen Free and Pb Free)
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.
Applications
 Desk Lights and Room Lighting
 Industrial Display Backlight
Marking Information
RT8474A
GSPYMDNN
RT8474AGSP : Product Number
YMDNN : Date Code
Simplified Application Circuit
V_IN
Analog Dimming
or PWM Dimming
R5
C1
RT8474A
VCC
C5
ISP
ISN
CTL
R1
R2
C2
SW
VC
CREG
OVP
C3
GND
R_SENSE
L1
D1
C4 R4
R3
Copyright ©2015 Richtek Technology Corporation. All rights reserved.
DS8474A-05 April 2015
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
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