MP2303 – 3A, 28V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER

INITIAL RELEASE – SPECIFICATIONS SUBJECT TO CHANGE

MP2303 Rev. 0.92

www.MonolithicPower.com

4

5/2/2006

MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.

© 2006 MPS. All Rights Reserved.

TM

PIN FUNCTIONS

SOIC8N

Pin #

3x3

QFN10

Pin #

Name

Description

1

9

BS

High-Side Gate Drive Boost Input. BS supplies the drive for the high-side N-

Channel MOSFET switch. Connect a 0.01µF or greater capacitor from SW to BS

to power the high side switch.

2

1

IN

Power Input. IN supplies the power to the IC, as well as the step-down converter

switches. Drive IN with a 4.75V to 28V power source. Bypass IN to GND with a

suitably large capacitor to eliminate noise on the input to the IC. See Input

Capacitor.

3

2

SW

Power Switching Output. SW is the switching node that supplies power to the

output. Connect the output LC filter from SW to the output load. Note that a

capacitor is required from SW to BS to power the high-side switch.

4

3, 4, 5

GND

Ground. SOIC8: Connect the exposed pad to pin 4. 3x3 QFN10: Connect to pins

3, 4 and 5 and ensure that said pins are tied together.

5

6

FB

Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB

with a resistive voltage divider from the output voltage. The feedback reference

voltage is 0.8V. See Setting the Output Voltage.

6

7

COMP

Compensation Node. COMP is used to compensate the regulation control loop.

Connect a series RC network from COMP to GND to compensate the regulation

control loop. In some cases, an additional capacitor from COMP to GND is

required. See Compensation Components.

7

8

EN

Enable Input. EN is a digital input that turns the regulator on or off. Drive EN higher

than 2.7V to turn on the regulator, drive it lower than 1.1V to turn it off. Pull up to

the IN pin with 100kΩ resistor for automatic startup.

8

10

SS

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

SS to GND to set the soft-start period. See Soft-Start Capacitor.