MP4458 – 1A, 4MHz, 36V STEP-DOWN CONVERTER

MP4458 Rev. 1.02

www.MonolithicPower.com

4

3/4/2013

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

© 2013 MPS. All Rights Reserved.

PIN FUNCTIONS

Pin #

Name

Description

1, 2

SW

ground is required. The rectifier must be close to the SW pins to reduce switching spikes.

3

EN

Enable Input. Pulling this pin below the specified threshold shuts the chip down. Pulling it up

above the specified threshold or leaving it floating enables the chip.

4

COMP

Compensation. This node is the output of the GM error amplifier. Control loop frequency

compensation is applied to this pin.

5

FB

Feedback. This is the input to the error amplifier. An external resistive divider connected

between the output and GND is compared to the internal +0.8V reference to set the

regulation voltage.

6

GND,

Exposed

Pad

Ground. It should be connected as close as possible to the output capacitor avoiding the high

current switch paths. The exposed pad and GND pin must be connected to the same ground

plane.

7

FREQ

Switching Frequency Program Input. Connect a resistor from this pin to ground to set the

switching frequency.

8, 9

VIN

Input Supply. This supplies power to all the internal control circuitry, both BS regulators and

the high-side switch. A decoupling capacitor to ground must be placed close to this pin to

minimize switching spikes.

10

BST

Bootstrap. This is the positive power supply for the internal floating high-side MOSFET driver.

Connect a bypass capacitor between this pin and SW pin.