1.5 MHZ, 600MA SYNCHRONOUS STEP-DOWN CONVERTER
FSP3100
FEATURES
High Efficiency : Up to 96%
1.5MHz Constant Switching Frequency
600mA Output Current at V
IN
=3.0V
Integrated Main switch and synchronous rectifier.
No Schottky Diode Required
2.5V to 5.5V Input Voltage Range
Output Voltage as low as 0.6V
100% Duty Cycle in Dropout
Low Quiescent Current : 300uA
＜1uA
Shutdown Current
Slope Compensated Current Mode Control for
Excellent Line and Load Transient Response
Short Circuit and Thermal Fault Protection
Space Saving 5-pin SOT23 packages
GENERAL DESCRIPTION
The FSP3100 is a 1.5MHz constant frequency; slope
compensated current mode PWM step-down
converter. The device integrates a main switch and a
synchronous rectifier for high efficiency without an
external Schottky diode. It is ideal for powering
portable equipment that runs from a single cell
lithium-Ion (Li+) battery. The FSP3100 can supply
600mA of load current from a 2.5V to 5.5V input
voltage. The output voltage can be regulated as low as
0.6V. The FSP3100 can also run at 100% duty cycle for
low dropout operation, extending battery life in portable
system. Idle mode operation at light loads provides
very low output ripple voltage for noise sensitive
applications.
The FSP3100 is offered in a low profile (1mm) 5-pin,
SOT package, and is available in an adjustable version
and fixed output voltage of 1.2V, 1.5V and 1.8V.
APPLICATIONS
Cellular and Smart Phones
PDAs
MP3 Player
Digital Still and Video Cameras
Portable instruments
Microprocessors and DSP Core Supplies
Wireless and DSL Modems
PIN CONFIGURATION
(Top View)
Run
GND
1
2
3
5
V
FB
/V
OUT
SW
4
V
IN
PIN DESCRIPTION
Pin Number
1
2
3
4
Pin Name
RUN
GND
SW
IN
Pin Function
Regulator Enable control input. Drive RUN above 1.5V to turn on the part.
Drive RUN below 0.3V to turn it off. In shutdown, all functions are disable
drawing
＜1uA
supply current. Do not leave RUN floating.
Ground
Power Switch Output. It is the Switch node connection to inductor. This pin
connects to the drains of the internal P-CH and N-CH MOSFET switches.
Supply Input Pin. Must be closely decoupled to GND, pin2, with a 2.2uF or
greater ceramic capacitor.
VFB (FSP3100): Feedback Input Pin. Connected FB to the center point of
the external resistor divider. The feedback threshold voltage is 0.6V.
VOUT (FSP3100-1.2/1.5/1.8): Output Voltage Feedback Pin. An internal
resistive divider divides the output voltage down for comparison to the
internal reference voltage.
5
FB/VOUT
1/11
2007-1-29
FOSLINK [ FOSLINK SEMICONDUCTOR CO.,LTD ]
