FSP3603 Datasheet, PDF (1/9 Pages) FOSLINK SEMICONDUCTOR CO.,LTD – 1.2MHZ MICROPOWER SYNCHRONOUS STEP-UP CONVERTER

1.2MHZ MICROPOWER SYNCHRONOUS STEP-UP CONVERTER
„ FEATURES
z High Efficiency: Up to 92%
z 1.2MHz Constant Switching Frequency
z 3.3V Output Voltage at I_OUT=100mA from a
Single AA Cell; 3.3V Output Voltage at
I_OUT=400mA from two AA cells
z Low Start-up Voltage: 0.85V
z Integrated main switch and synchronous rectifier. No
Schottky Diode Required
z 2.5V to 5V Output Voltage Range
z Automatic Pulse Skipping Mode Operation
z Tiny External Components
z <1 µA Shutdown Current
z Antiringing Control Reduces EMI
z Space Saving 6-Pin Thin SOT23 Package
FSP3603
„ GENERAL DESCRIPTION
The FSP3603 is a 1.2MHz constant frequency, current
mode PWM step-up converter. It can supply 3.3V
output voltage at 100mA from a single AA Cell. The
device integrates a main switch and a synchronous
rectifier for high efficiency without an external Schottky
diode. A switching frequency of 1.2MHz allows the use
of tiny, low profile inductors and ceramic capacitors.
The current mode PWM operation with internal
compensation provides excellent line and load
transient characteristics. The FSP3603 features Pulse
Skipping Mode operation at light loads to avoid
unacceptable ripple voltage.
The FSP3603 is offered in a low profile (1mm) small
6-Pin SOT23 Package
„ APPLICATIONS
z Cellular and Smart Phones
z Microprocessors and DSP Core Supplies
z Wireless and DSL Modems
z MP3 Player
z Digital Still and Video Cameras
z Portable Instruments
„ PIN CONFIGURATION
(Top View)
VIN VOUT SHDN
65 4
Pin Number
1
2
3
4
5
6
Pin Name
SW
GND
FB
SHDN
VOUT
VIN
1 23
SW GND FB
Pin Function
Power Switch Pin. It is the switch node connection to Inductor.
Ground Pin
Feedback Input Pin. Connect FB to the center point of the external resistor
divider. The feedback threshold voltage is 1.23V.
Chip Shutdown Signal Input. Logic high is normal operation mode, Logic
Low is Shutdown. Typically, this pin is connected to V_IN through a 1 MΩ
resistor.
Power Output Pin. V_OUT is held 0.6V below than V_IN in shutdown.
Power Supply Input. Must be closely decoupled to GND, Pin 2, with a 4.7µF
or greater ceramic capacitor.
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2007-4-19