MP8761

High Efficiency, 8A, 18V,

Synchronous, Step-Down Converter

MP8761 Rev. 1.1

www.MonolithicPower.com

1

11/4/2013

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

© 2013 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The MP8761 is a fully-integrated, high-

frequency, synchronous, rectified, step-down,

switch-mode converter. It offers a very compact

solution to achieve a 8A output current over a

wide input-supply range with excellent load and

line regulation. The MP8761 operates at high

efficiency over a wide output-current load range.

The MP8761 uses Constant-On-Time (COT)

control mode to provide fast transient response

and ease loop stabilization.

An external resistor programs the operating

frequency

from

200kHz

to

1MHz.

The

frequency stays nearly constant as the input

supply

varies

with

the

feed-forward

compensation.

The default under voltage lockout threshold is

4.1V, but a resistor network on the enable pin

can increase this threshold. The soft start pin

controls the output voltage startup ramp. An

open drain power good signal indicates that the

output is within nominal voltage range.

It has full integrated protection features that

include over-current protection, over-voltage

protection and thermal shutdown.

The MP8761 is available in a 3mm×4mm QFN

package, and requires a minimal number of

readily-available components.

FEATURES

• 2.5V to 5V Operating Input Range with

External 5V Bias

• 4.5V to 18V Operating Input Range with

Internal Bias

• 8A Output Current

• Proprietary Switching-Loss-Reduction

Technique

• Adaptive COT for Ultrafast Transient

Response

• 1.5% Reference Voltage Over Junction

Temperature Range (−40°C to +125°C)

• Programmable Soft-Start Time

• Pre-Bias Start-Up

• Programmable Switching Frequency from

200kHz to 1MHz

• Non-Latch OCP, OVP, and Thermal

Shutdown

• Output Adjustable from 0.611V to 13V

APPLICATIONS

•

Set-Top Boxes

•

XDSL Modem/DSLAM

•

Small-Cell Base Stations

•

Personal Video Recorders

•

Flat-Panel Televisions and Monitors

•

Distributed Power Systems

All MPS parts are lead-free and adhere to the RoHS directive. For MPS green

status, please visit MPS website under Products, Quality Assurance page.

“MPS” and “The Future of Analog IC Technology” are registered trademarks of

Monolithic Power Systems, Inc.

TYPICAL APPLICATION

IN

FREQ

VCC

EN

PGND

BST

FB

SW

MP8761

ON/OFF

C1

C5

C3

L1

R4

C4

R1

R2

C2

R3

PG

AGND

SS

C6

0.01

0.1

1

10

30

40

50

60

70

80

90

100