APW7209
1MHz, High-Efficiency, Step-Up Converter for 2 to 10 White LEDs
Features
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Wide Input Voltage from 2.5V to 6V
0.3V Reference Voltage
Fixed 1MHz Switching Frequency
High Efficiency up to 88%
100Hz to 100kHz PWM Brightness Control Fre-
quency
Open-LED Protection
Under-Voltage Lockout Protection
Over-Temperature Protection
<1µA Quiescent Current during Shutdown
SOT-23-6 Package
Lead Free and Green Devices Available
(RoHS Compliant)
General Description
The APW7209 is a current-mode and fixed frequency
boost converter with an integrated N-FET to drive up to 10
white LEDs in series.
The series connection allows the LED current to be iden-
tical for uniform brightness. Its low on-resistance of N-
FET and low feedback voltage reduce power loss and
achieve high efficiency. Fast switching frequency(1MHz
typical) allows using small-size inductor and both of in-
put and output capacitors. An over voltage protection
function, which monitors the output voltage via OVP pin,
stops switching of the IC if the OVP voltage exceeds the
over voltage threshold. An internal soft-start circuit elimi-
nates the inrush current during start-up.
The APW7209 also integrates under-voltage lockout, over-
temperature protection, and current limit circuits to pro-
tect the IC in abnormal conditions.The APW7209 is avail-
able in a SOT-23-6 package.
Applications
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White LED Display Backlighting
Cell Phone and Smart Phone
PDA, PMP, MP3
Digital Camera
Simplified Application Circuit
V
IN
L1
22µH
V
OUT
Pin Configuration
SOT-23-6 Top View
LX 1
GND 2
FB 3
6 VIN
5 OVP
4 EN
C1
4.7µF
6
2
4
VIN
GND
EN
LX
OVP
FB
1
5
3
C2
1µF
Up to
10
WLEDs
APW7209
OFF ON
R1
15Ω
ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and
advise customers to obtain the latest version of relevant information to verify before placing orders.
Copyright
©
ANPEC Electronics Corp.
Rev. A.3 - Jul., 2008
1
www.anpec.com.tw
ANPEC [ ANPEC ELECTRONICS COROPRATION ]
