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Liteon Semiconductor Corporation
LSP3170
2A Step Down DC/DC Converter
Rev1.5
1/10
PIN ASSIGNMENT
(Top View)
PIN DESCRIPTION
Name
No.
Description
BS
1
Bootstrap. This pin acts as the positive rail for the high-side switch’s gate driver.
Connect a 0.1uF capacitor between BS and SW.
IN
2
Input Supply. Bypass this pin to G with a low ESR capacitor. See Input Capacitor
in the Application Information section.
SW
3
Switch Output. Connect this pin to the switching end of the inductor.
G
4
Ground.
FB
5
Feedback Input. The voltage at this pin is regulated to 1.222V. Connect to the
resistor divider between output and ground to set output voltage.
COMP
6
Compensation Pin. See Stability Compensation in the Application Information
section.
EN
7
Enable Input. When higher than 2.5V, this pin turns the IC on. When lower than
2.0V, this pin turns the IC off. Output voltage is discharged when the IC is off.
When left unconnected, EN is pulled high internally.
N/C
8
Not Connected.
TYPICAL APPLICATION
TFT LCD Monitors
Portable DVDs
Car-Powered or Battery-Powered Equipments
Set-Top Boxes
Telecom Power Supplies
DSL and Cable Modems and Routers
Termination Supplies
GENERAL DESCRIPTION
The LSP3170 is a current-mode step-down DC/DC
converter that generates up to 2A of output current at
400kHz switching frequency.
Consuming only 40A in shutdown mode, the
LSP3170 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 LSP3170 is available in a SOP8L package and
requires very few external devices for operation.
FEATURES
2A Output Current
Up to 95% Efficiency
4.6V to 24V Input Range
40A Shutdown Supply Current
400kHz Switching Frequency
Adjustable Output Voltage
Cycle-by-Cycle Current Limit Protection
Thermal Shutdown Protection
Frequency Foldback at Short Circuit
Stability with Wide Range of Capacitors,
Including Low ESR Ceramic Capacitors
SOP8L Package