FSP3129 Datasheet, PDF (1/10 Pages) FOSLINK SEMICONDUCTOR CO.,LTD – WIDE INPUT 2A STEP-DOWN CONVERTER

WIDE INPUT 2A STEP-DOWN CONVERTER
„ FEATURES
z 2A Output Current
z Up to 95% Efficiency
z Up to 30V Input Range
z 6µA Shutdown Supply Current
z 400kHz Switching Frequency
z Adjustable Output Voltage
z Cycle-by-Cycle Current Limit Protection
z Thermal Shutdown Protection
z Frequency Fold Back at Short Circuit
z Stability with Wide Range of Capacitors,
Including Low ESR Ceramic Capacitors
z SOP8L Package
„ TYPICAL APPLICATION
z TFT LCD Monitors or Televisions and HDTV
z Portable DVD Players
z Car-Powered or Battery-Powered Equipment
z Set-Top Boxes
z Telecom Power Supplies
z DSL and Cable Modems and Routers
FSP3129
„ GENERAL DESCRIPTION
The FSP3129 is a current-mode step-down DC/DC
converter that generates up to 2A output current at
400kHz switching frequency. The device can
operate with input voltage up to 30V.
Consuming only 6µA in shutdown mode, the
FSP3129 is highly efficient with peak efficiency at
95% when in operation. Protection features include
cycle-by-cycle current limit, thermal shutdown, and
frequency fold back at short circuit.
The FSP3129 is available in SOP8L package and
requires very few external devices for operation.
„ PIN ASSIGNMENT
(Top View)
BS 1
IN 2
SW 3
G4
8 N/C
7 EN
6 COMP
5 FB
„ PIN DESCRIPTION
Pin Number Pin Name
Pin Description
Bootstrap. This pin acts as the positive rail for the high-side switch’s gate driver.
1
BS _{Connect a 10nF between this pin and SW.}
2
IN
Input Supply. Bypass this pin to G with a low ESR capacitor. See Input Capacitor in
Application Information section.
3
SW Switch Output. Connect this pin to the switching end of the inductor.
4
G
Ground.
5
FB
Feedback Input. The voltage at this pin is regulated to 1.222V. Connect to the resistor
divider between the output and ground to set output voltage.
6
COMP Compensation Pin. See Compensation Technique in Application information section.
Enable Input. Drive higher than 1.3V or unconnected to enable the IC. Drive lower than
7
EN
0.7V to disable the IC. The IC is in 6µA low current shutdown mode and the output is
discharged through the Low-Side Power Switch. This pin has a small internal pull up
current to a high level voltage when pin is not connected.
8
N/C Not Connected.
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2007-1-4