A707
www.addmtek.com
DESCRIPTION
The A707 is a high voltage Boost driver with 3 channels
adjustable constant current regulators for notebook LED
backlight applications. Three 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 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 sense 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.
H
IGH
V
OLTAGE
B
OOST
D
RIVER
W
ITH
3 C
HANNELS
C
ONSTANT
C
URRENT
R
EGULATORS
FEATURES
High frequency DC/DC converter for LEDs.
Integrated 40V power MOSFET.
4.5V ~ 25V wide input voltage range.
3 constant-current output channels.
Output current adjustable through external resistor.
Constant output current range: 5mA~30mA.
40V output sustaining voltage for up to 10 pcs of LEDs
in series.
LED open/short protection.
TSSOP-14L Green Package.
APPLICATIONS
Automotive interior lighting
LED backlight driver for NB and Monitors.
TYPICAL APPLICATION CIRCUIT
V
IN
=4.5V~25V
C
IN
L
D
F
PACKAGE PIN OUT
V
OUT
C
OUT
PWM
PWM
PWM
SW
GND
1
2
3
4
5
6
7
14
13
12
11
10
9
8
SW
GND
OUT3
OUT2
OUT1
COMP
SS
SHDN
BYP
VIN
OUT3
ON/OFF
SHDN
BYP
RT
CVFB
ISET
C
BP
VIN
RT
A707
COMP
CVFB
OUT2
OUT1
ISET
R
T
SS
－
V
LED
＋
TSSOP-14
(Top View)
R
SET
C
SS
R
SS
R
P
C
P1
R
1
R
2
ORDER INFORMATION
F
TSSOP
14 pin
A707FGT
Note: The letter “G” is marked for Green parts, and letter “T” is marked for Tape & Reel.
Copyright
©
2008 ADDtek Corp.
1
V1.2 -- DECEMBER 2008
ADDTEK [ ADDTEK CORP ]
