NB681

28V, 6A, Low Iq, High Current

Synchronous Buck Converter with 2-Bit VID

NB681 Rev. 1.04

www.MonolithicPower.com

1

12/28/2017

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© 2017 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The NB681 is a fully integrated, high-frequency,

synchronous, rectified, step-down, switch-mode

converter with 2-bit VID, especially designed for

IMVP8

applications—VCCIO,

PRIMCORE,

V1.0A, EDRAM, and EOPIO. It offers a very

compact solution to achieve a 6A continuous

output current and a 7.5A peak output current

over a wide input supply range.

The NB681 operates at high efficiency over a

wide output current load range based on MPS

proprietary switching loss reduction technology

and internal low Ron power MOSFETs.

Adaptive constant-on-time (COT) control mode

provides fast transient response and eases loop

stabilization. The DC auto-tune loop provides

good load and line regulation.

To avoid audible noise, NB681 provides low-

power mode for power loss saving during the

low-power state and ultrasonic mode.

Full protection features include OC limit, OVP,

UVP, and thermal shutdown.

The converter requires a minimal number of

external components, and it is available in a QFN

2mm x 3 mm package.

FEATURES

 Wide 4.5V to 28V Operating Input Range

 VCCIO/PRIMCORE/EDRAM/EOPIO/V1.0A

Compatible for IMVP8

 Output Adjustable by 2-Bit VID

 Low-Power Mode

 25µA Low Quiescent Current

 6A Continous Output Current

 7.5A Peak Output Current

 Selectable Ultrasonic Mode

 Adaptive COT for Fast Transient

 DC Auto-Tune Loop

 Stable with POSCAP and Ceramic

Capacitors

 1% Reference Voltage

 Internal Soft Start

 Output Discharge

 OCL, OVP, UVP, and Thermal Shutdown,

 Latch-Off Reset via EN or Power Cycle

 QFN 2mm x 3mm Package

APPLICATIONS



Laptop Computers



Tablet PCs



Networking Systems



Servers



Personal Video Recorders



Flat Panel Televisions and Monitors



Distributed Power Systems

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

MPS green status, please visit the MPS website under Quality Assurance.

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

Monolithic Power Systems, Inc.

TYPICAL APPLICATION