MP9472–0.45A, 18V, NON-SYNCHRONOUS, RECTIFIED, STEP-DOWN CONVERTER

MP9472 Rev. 1.0

www.MonolithicPower.com

5

12/9/2015

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2015 MPS. All Rights Reserved.

PIN FUNCTIONS

Pin #

Name

Description

1

SS

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.

2

EN

Enable input.

EN is a digital input that turns the regulator on or off. Drive EN high to turn on

the regulator; drive EN low to turn off the regulator. Pull EN up with a 100kΩ resistor for

automatic start-up.

3

COMP

Compensation node.

Connect a series RC network from COMP to GND to compensate for

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

required. See the Compensation Components section on page 12 for details.

4

FB

Feedback input.

FB senses and regulates the output voltage. Drive FB with a resistive

voltage divider from the output voltage. The feedback threshold is 0.923V. See the Setting the

Output Voltage section on page 11 for details.

5

GND

Ground.

6

SW

Power switching output.

SW is the switching node that supplies power to the output.

ground. Note that a capacitor is required from SW to BST to power the high-side switch.

7

IN

Power input.

IN supplies power to the IC, as well as the step-down converter switches. Drive

IN with a 4.75V to 18V power source. Bypass IN to GND with a sufficiently large capacitor to

eliminate noise on the input to the IC. See the Selecting the Input Capacitor section on page

11 for details.

8

BST

High-side gate drive boost input.

BST supplies the drive for the high-side N-channel

MOSFET switch. Connect a 0.01μF capacitor from SW to BST to power the high-side switch.