CM3708A
3A L
OW
-N
OISE
PWM S
TEP
-D
OWN
R
EGULATOR
GENERAL DESCRIPTION
The CM3708A is a low-noise, pulse-width-modulated (PWM),
DC-DC step-down converter. It powers logic and transmitters
in small wireless systems such as cellular phones,
communicating PDAs, and handy-terminals. The device
features an internal synchronous rectifier for high efficiency; it
requires no external Schottky diode. Excellent noise
characteristics and fixed-frequency operation provide easy
post-filtering. The CM3708A is ideally suited for Li-lon battery
applications. It is also useful for +3V or +5V fixed input
applications.
The device operates in one of four modes. Forced PWM
mode operates at a fixed frequency regardless of the load.
Shutdown mode places the device in standby, reducing
quiescent supply current to under 0.1μA.
The CM3708A can deliver over 3.0A. The output voltage can
be adjusted from VREF to VIN. The input range is from 2.0V
to 5.5V. Other features of the CM3708A include high
efficiency, low dropout voltage. It is available in a
space-saving 16-pin SOP & TSSOP package.
FEATURES
Patent Filed #6,452,366
600KHz switching and synchronization
Dynamic output-voltage adjustment from VREF to VIN
3A Guaranteed Output Current
95% Efficiency
No Schottky Diode Required
16-pin PSOP/PTSSOP power packages
6A Low Noise Current Limit Protection
External Soft Start
Rail to Rail output Buck Converter
APPLICATIONS
Cellular Phone
Cordless Phone
PDAs and Handy-Terminals
AGP Chipset Supplies
CPU I/O Supplies
Notebook Chipset Supplies
Battery Operated Devices
PIN CONFIGURATION
PSOP-16 (PS16) / PTSSOP-16 (PT16)
Top View
1
2
3
4
5
6
7
8
VIN2
PVIN2
LX2
PGND2
AGND
VFB
NC
AGND
16
15
14
13
12
11
10
9
VIN1
PVIN1
LX1
PGND1
AGND
SD
VREF
AGSEN
2007/02/13 Rev1.3
Champion Microelectronic Corporation
Page 1
CHAMP [ CHAMPION MICROELECTRONIC CORP. ]
