NB669

24V, High Current

Synchronous Buck Converter With LDO

NB669 Rev. 1.01

www.MonolithicPower.com

1

7/23/2013

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© 2013 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The NB669 is a fully integrated high frequency

synchronous rectified step-down switch mode

converter with 5V fixed output voltage. It offers

very compact solution to achieve 6A continuous

output current and 9A peak output current over

a wide input supply range with excellent load

and line regulation. The NB669 operates at high

efficiency over a wide output current load range.

Constant-On-Time

(COT)

control

mode

provides fast transient response and eases loop

stabilization.

Under voltage lockout is internally set as 4.15 V.

An open drain power good signal indicates the

output is within its nominal voltage range.

NB669 also provides a 5V LDO, which can be

used to power the external peripheries, such as

the keyboard controller in the laptop computer.

A 300kHz CLK is also available; its output can

be used to drive an external charge pump,

generating gate drive voltage for the load

switches without reducing the main converter’s

efficiency.

Full protection features include OCP, OVP,

UVP and thermal shut down.

The converter requires minimum number of

external components and is available in QFN16

(3mmx3mm) package.

FEATURES

• Wide 6.5V to 24V Operating Input Range

• 5V Fixed Output Voltage

• Built-in 5V, 100mA LDO with Switches

• 6A Continuous Output Current

• 9A Peak Output Current

• 300kHZ CLK for External Charge Pump

• Proprietary Switching Loss Reduction

Technique

• Internal Soft Start

• Output Discharge

• 500kHZ Switching Frequency

• OCP, OVP, UVP Protection and Thermal

Shutdown

APPLICATIONS

•

Laptop Computer

•

Tablet PC

•

Networking Systems

•

Personal Video Recorders

•

Flat Panel Television 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