LSP5502

2A Synchronous Step Down DC/DC Converter

1/11

Rev. 1.7

www.liteon-semi.com

PIN ASSIGNMENT

18

7

6

5

2

3

4

SS

EN

COMP

FB

BS

IN

SW

GND

(TOP View)

SOP-8L

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 0.01uF 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.

GND

4

Ground.

FB

5

Feedback Input. The voltage at this pin is regulated to 0.925V. 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

1.3V, this pin turns the IC off. Output voltage is discharged when the IC is off. This

pin should not be left open.

SS

8

Soft-Start Control Input. SS controls the soft-start period. Connect a capacitor from

SS to GND to set the soft-start period. A 0.1µF capacitor sets the soft-start period

to 15ms. To disable the soft-start feature, leave SS unconnected.

TYPICAL APPLICATION

Distributed Power Systems

Networking Systems

FPGA, DSP, ASIC Power Supplies

Green Electronics/ Appliances

Notebook Computers

GENERAL DESCRIPTION

The LSP5502 is a monolithic synchronous buck

regulator. The device integrates 120mΩ MOSFETS

that provide 2A continuous load current over a wide

operating input voltage of 4.5V to 27V. Current mode

control

provides

fast

transient

response

and

cycle-by-cycle current limit.

An adjustable soft-start prevents inrush current at turn

on. In shutdown mode, the supply current drops

below 1µA.

This device, available in an 8-pin SOP package,

provides a very compact system solution with minimal

reliance on external components.

FEATURES

2A Output Current

Wide 4.5V to 27V Operating Input Range

Integrated 120mΩ Power MOSFET Switches

Output Adjustable from 0.925V to 24V

Up to 96% Efficiency

Programmable Soft-Start

Stable with Low ESR Ceramic Output Capacitors

Fixed 400KHz Frequency

Cycle-by-Cycle Over Current Protection

Input Under Voltage Lockout

8-Pin SOP Package

Free Datasheet http://www.nDatasheet.com