®
RT4503/A
Asynchronous Boost Converter for 10 WLEDs
General Description
The RT4503/A is a highly integrated LED driver IC capable
of driving 10 WLEDs in series. It is composed of a current
mode Boost converter integrated with a 36V/1.2A power
switch.
The RT4503/A supports a wide input voltage range from
2.5V to 5.5V and runs at a fixed frequency of 550kHz.
The LED current is set via an external resistor and the
feedback voltage is regulated to 200mV.
For brightness dimming, the RT4503A supports 32 steps
pulse dimming which determines the feedback reference
voltage, and RT4503 support PWM dimming which
determines the feedback reference voltage.
Features
2.5V to 5.5V Input Voltage Range
36V Open LED Protection for 10 WLEDs
Pulse Dimming Brightness Control
200mV Reference Voltage with
±
2% Accuracy
550kHz Switching Frequency
Built-In Soft-Start
Over-Temperature Protection
Internal Compensation
Current Limit
Ordering Information
RT4503/A
Package Type
QW : WDFN-6L 2x2 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
RT4503 : PWM Dimming
RT4503A : Pulse Dimming
Note :
Richtek products are :
�½
Applications
Cellular Phones
Digital Cameras
Probable Instruments
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.
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Simplified Application Circuit
L
LX
V
IN
VIN
RT4503/A
EN
GND
COMP*
FB
…
* : COMP pin for RT4503 only.
Copyright
©
2015 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS4503/A-03 June 2015
www.richtek.com
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