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 lowpower 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