eorex

EP4001

Aug. 2006

www.eorex.com

1/10

High Efficiency, Step-Up Converter with EXT

Features

• Low Start-up Voltage: 1.0V

• 35μA Quiescent Supply Current in Switch-off

mode

• <1μA Shutdown Current

• 90% Efficiency

• Excellent Load and Line Regulation

Characteristics

• 350mΩ Internal MOSFET

• 450KHz Fixed Switching Frequency

• Small 6-Lead SOT-23 Package

Applications

• PDA

• DSC

• LCD Panel

• RF-Tags

• MP3

• Portable Equipment

• Wireless key board and mouse

Description

The EP4001 is a micropower, high efficiency, and

low voltage step-up DC/DC converter intended

for use in battery powered wireless applications.

With the low start-up input voltage below 1V, the

device is suitable for applications with 1 or 2 AA

cells, providing up to 300mA output current at

3.3V output. The 35µA low quiescent current,

zero shutdown current and high efficiency

maintains long battery lifetime. A switching

frequency of 450KHz minimizes solution footprint

by allowing the use of small inductors and

ceramic capacitors. The device is offered in a low

profile (1mm) small 6-lead SOT-23 package.

The current mode PWM design is optimized for

stable and high efficiency operations over a wide

range of load currents. With low resistance

internal

MOSFET

switches,

the

EP4001

maintains high efficiency over a wide range of

load current. In addition to its high efficiency at

moderate and heavy loads, the EP4001 includes

automatic PFM operation that improves efficiency

of the power converter at light loads.

Typical Application

⎟

⎠

⎞

⎜

⎝

⎛

+

R2

R1

1

Where FB=1.22V

Figure 1-Basic application circuit with EP4001