APW7136A_10 Datasheet, PDF (1/17 Pages) Anpec Electronics Coropration – 1MHz, High-Efficiency, Step-Up Converter for 2 to 8 White LEDs

APW7136A/B/C
1MHz, High-Efficiency, Step-Up Converter for 2 to 8 White LEDs
Features
General Description
• Wide Input Voltage from 2.7V to 6V
• 0.25V Reference Voltage
• Fixed 1MHz Switching Frequency
• High Efficiency up to 87%
• 100Hz to 100kHz PWM Brightness Control
Frequency
• Open-LED Protection
• Under-Voltage Lockout Protection
• Over-Temperature Protection
• <1µA Quiescent Current Dduring Shutdown
• SOT-23-6 Packages
• Lead Free and Green Devices Available
(RoHS Compliant)
The APW7136A/B/C is a current-mode and fixed frequency
boost converter with an integrated N-FET to drive up to 8
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 feedback voltage reduce power loss and achieve
high efficiency. Fast 1MHz current-mode PWM operation
is available for input and output capacitors and a small
inductor while minimizing ripple on the input supply. The
OVP pin monitors the output voltage and stops switching
if exceeds the over-voltage threshold. An internal soft-
start circuit eliminates the inrush current during start-up.
The APW7136A/B/C also integrates under-voltage
lockout, over-temperature protection, and current-limit
circuits. The APW7136/A/B/C is available in a SOT-23-6
packages.
Applications
• White LED Display Backlighting
• Cell Phone and Smart Phone
• PDA, PMP, MP3
• Digital Camera
Pin Configuration
Simplified Application Circuit
V_IN
C1
4.7µF
OFF ON
L1
22µH
6 _VIN
LX ¹
2 _{GND OVP} 5
4 _EN
FB ³
V_OUT
C2
1µF Up to 8
WLEDs
R1
12Ω
SOT-23-6 Top View
LX 1
GND 2
FB 3
6 VIN
5 OVP
4 EN
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.
1
Rev. A.4 - Dec., 2010
www.anpec.com.tw