1 Features

1• Thin SOT-6 Package

• 3-V to 20-V Input Voltage Range

• 0.8-V to 18-V Output Voltage Range

• 1-A Output Current

• 550-kHz (LM2734Y) and 1.6-MHz (LM2734X)

Switching Frequencies

• 300-mΩ NMOS Switch

• 30-nA Shutdown Current

• 0.8-V, 2% Internal Voltage Reference

• Internal Soft Start

• Current-Mode, PWM Operation

• Thermal Shutdown

• Create a Custom Design Using the LM2734 With

WEBENCH® Power Designer

2 Applications

• Local Point-of-Load Regulation

• Core Power in HDDs

• Set-Top Boxes

• Battery-Powered Devices

• USB Powered Devices

• DSL Modems

• Notebook Computers

3 Description

The LM2734 regulator is a monolithic, highfrequency,

PWM step-down DC/DC converter in a 6-

pin Thin SOT package. The device provides all the

active functions to provide local DC/DC conversion

with fast transient response and accurate regulation

in the smallest possible PCB area.

With a minimum of external components and online

design support through WEBENCH, the LM2734

regulator is easy to use. The ability to drive 1-A loads

with an internal 300-mΩ NMOS switch using state-ofthe-

art 0.5-μm BiCMOS technology results in the best

power density available. The world-class control

circuitry allows for on-times as low as 13 ns, thus

supporting exceptionally high-frequency conversion

over the entire 3-V to 20-V input operating range

down to the minimum output voltage of 0.8 V.

Switching frequency is internally set to 550 kHz

(LM2734Y) or 1.6 MHz (LM2734X), allowing the use

of extremely small surface-mount inductors and chip

capacitors. Even though the operating frequencies

are very high, efficiencies up to 90% are easy to

achieve. External shutdown is included, featuring an

ultra-low standby current of 30 nA.

The LM2734 regulator uses current-mode control and

internal compensation to provide high-performance

regulation over a wide range of operating conditions.

Additional features include internal soft-start circuitry

to reduce inrush current, pulse-by-pulse current limit,

thermal shutdown, and output overvoltage protection.