FSP3126 Datasheet, PDF (1/9 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 4.75V to 20V Input Range
z 8µA Shutdown Supply Current
z 410kHz Switching Frequency
z Adjustable Output Voltage
z Cycle-by-Cycle Current Limit Protection
z Thermal Shutdown Protection
z Frequency Foldback at Short Circuit
z Stability with Wide Range of Capacitors,
Including Low ESR Ceramic Capacitors
z SOP8L Package
„ Typical Application
z TFT LCD Monitors
z Portable DVDs
z Car-Powered or Battery-Powered Equipments
z Set-Top Boxes
z Telecom Power Supplies
z DSL and Cable Modems and Routers
z Termination Supplies
FSP3126
„ GENERAL DESCRIPTION
The FSP3126 is a current-mode step-down DC/DC
converter that generates up to 2A of output current at
410kHz switching frequency. The device utilizes
ISOBCD20 process for operation with input voltages
up to 20V.
Consuming only 8µA in shutdown mode, the
FSP3126 is highly efficient with peak operating
efficiency at 95%. Protection features include
cycle-by-cycle current limit, thermal shutdown, and
frequency foldback at short circuit.
The FSP3126 is available in a 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
FSP3126
6 COMP
5 FB
„ PIN DESCRIPTION
Name
No.
BS
1
IN
2
SW
3
G
4
FB
5
COMP
6
EN
7
N/C
8
Description
Bootstrap. This pin acts as the positive rail for the high-side switch’s gate driver.
Connect a 10nF capacitor between BS and SW.
Input Supply. Bypass this pin to G with a low ESR capacitor. See Input Capacitor
in the Application Information section.
Switch Output. Connect this pin to the switching end of the inductor.
Ground.
Feedback Input. The voltage at this pin is regulated to 1.293V. Connect to the
resistor divider between output and ground to set output voltage.
Compensation Pin. See Stability Compensation in the Application Information
section.
Enable Input. When higher than 1.3V, this pin turns the IC on. When lower than
0.7V, this pin turns the IC off. Output voltage is discharged when the IC is off.
When left unconnected, EN is pulled up to 4.5V tip with a 2µA pull up current.
Not Connected.
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2007-5-28