LM3674_0609 Datasheet, PDF (1/15 Pages) National Semiconductor (TI) – 2MHz, 600mA Step-Down DC-DC Converter in SOT 23-5

September 2006
LM3674
2MHz, 600mA Step-Down DC-DC Converter in SOT 23-5
General Description
The LM3674 step-down DC-DC converter is optimized for
powering low voltage circuits from a single Li-Ion cell battery
and input voltage rails from 2.7V to 5.5V. It provides up to
600mA load current, over the entire input voltage range.
There are several fixed output voltages and adjustable out-
put voltage versions.
The device offers superior features and performance for
mobile phones and similar portable systems. During PWM
mode, the device operates at a fixed-frequency of 2 MHz
(typ). Internal synchronous rectification provides high effi-
ciency during PWM mode operation. In shutdown mode, the
device turns off and reduces battery consumption to 0.01 µA
(typ).
The LM3674 is available in SOT23-5 in leaded (PB) and
lead-free (NO PB) versions. A high switching frequency of 2
MHz (typ) allows use of only three tiny external surface-
mount components, an inductor and two ceramic capacitors.
Features
n 600mA max load current
n Input voltage range from 2.7V to 5.5V
n Available in fixed and adjustable output voltages ranging
from 1.0V to 3.3V
n Operates from a single Li-Ion cell Battery
n Internal synchronous rectification for high efficiency
n Internal soft start
n 0.01 µA typical shutdown current
n 2 MHz PWM fixed switching frequency (typ)
n SOT23-5 package
n Current overload protection and Thermal shutdown
protection
Applications
n Mobile phones
n PDAs
n MP3 players
n Portable instruments
n W-LAN
n Digital still cameras
n Portable Hard disk drives
Typical Application
FIGURE 1. Typical Application Circuit
20167201
© 2006 National Semiconductor Corporation DS201672
www.national.com