A723
www.addmtek.com
DESCRIPTION
The A723 is a high voltage Boost driver with 8 channels
adjustable constant current regulators for LED backlight
applications. Eight regulated current ports are designed to
provide uniform and pure DC constant current sinks for driving
LEDs within a large range V
F
variations. It can drive a number
of LEDs in series/parallel configuration.
Users may adjust the output current from 5mA to 30mA
through an external resistor, R
SET
, which gives users flexibility
in controlling the light intensity of LEDs. It also could adjust
LED brightness from 0% to 100% via PWM pin with Pulse
Width Modulation signal.
A feedback circuit is built in the between of Boost Driver
and the Current Regulators. It could output the lowest dropout
voltage among used channels to Boost Driver in order to
maintain the output voltage in optimal level. An OVP circuit is
built for open-loop protection when any string becomes open.
The thermal protection function protects IC from over
temperature damage. Also, the exposed thermal pad enhances
the package power dissipation.
TYPICAL APPLICATION CIRCUIT
V
IN
= 4.5V~25V
C
IN
L
D
F
H
IGH
V
OLTAGE
B
OOST
D
RIVER
W
ITH
8 C
HANNELS
C
ONSTANT
C
URRENT
R
EGULATORS
FEATURES
High frequency DC/DC converter for LEDs.
Integrated 50V power MOSFET.
4.5V ~ 25V wide input voltage range.
8 constant-current output channels.
Output current adjustable through external resistor.
Constant output current range: 5mA~30mA.
45V current sinks breakdown voltage for up to 12
pcs of LEDs in series.
LED open/short protection.
Green Package.
APPLICATIONS
Automotive interior lighting
LED backlight driver for NB and Monitors.
PACKAGE PIN OUT
V
OUT
OUT1
OUT2
17
PWM
PWM
PWM
SW
OUT2
OUT1
OUT3
20
19
18
SHDN
OUT4
GND
OUT3
16
15
14
C
OUT
SW
1
2
OUT4
GND
GND
OUT5
OUT6
ON/OFF
SHDN
BYP
BYP
－
V
LED
＋
A723
C
BP
R
T
VIN
RT
CVFB
3
4
5
6
7
8
13
12
11
VIN
RT
CVFB
A723
COMP
OUT8
OUT7
GND
OUT5
OUT6
ISET
SS
9
10
ISET
SS
COMP
OUT8
R
SET
C
SS
R
P
C
P1
R
1
R
2
QFN 4mm x 4mm
(Top View)
ORDER INFORMATION
K
Green Part
Copyright
©
2009 ADDtek Corp.
QFN 4mm x 4mm
20 pin
A723KGT
Note: The letter “G” is marked for Green parts, and letter “T” is marked for Tape & Reel.
1
V0.8 -- FEBRUARY 2009
OUT7
ADDTEK [ ADDTEK CORP ]
