CM3706
1.5MHz, 600mA Synchronous
Step-Down Regulator
GENERAL DESCRIPTION
The CM3706 is a 1.5MHz constant frequency, slope
compensated current mode PWM step-down converter.
The device integrates a main switch and a synchronous
rectifier for high efficiency without an external Schottky
diode. It is ideal for powering portable equipment that runs
from a single cell lithium-Ion (Li+) battery. The CM3706
can supply 600mA of load current from a 2.5V to 5.5V
input voltage.
The output voltage can be regulated as
low as 0.6V. The CM3706 can also run at 100% duty cycle
for low dropout operation, extending battery life in portable
system. Idle mode operation at light loads provides very
low output ripple voltage for noise sensitive applications.
The CM3706 is offered in a low profile (1mm) 5-pin, thin
TSOT package, and is available in an adjustable version.
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FEATURES
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High Efficiency: Up to 96%
1.5Mhz Constant Switching Frequency
600mA Output Current at V
IN
=3V
Integrated Main switch and synchronous rectifier. No
Schottky Diode Required
2.5V to 5.5V Input Voltage Range
Output Voltage as Low as 0.6V
100% Duty Cycle in Dropout
Low Quiescent Current: 300µA
Slope Compensated Current Mode Control for Excellent Line
and Load Transient Response
Short Circuit Protection
Thermal Fault Protection
<1uA Shutdown Current
Space Saving 5-Pin Thin TSOT23 package
APPLICATIONS
Cellular and Smart Phones
MP3 Players
Portable Instruments
Digital Still and Video Cameras
Microprocessors and DSP Core Supplies
Wireless and DSL Modems
PDAs
TYPICAL APPLICATIONS
IN
2.5V TO
5.5V
Cin
4.7uF
4
3
2.2uH
V
IN
1
SW
634k
OUT
CM3706
RUN GND V
FB
2
316K
5
Cout
10uF
22PF
Figure 1. Basic Application Circuit with CM3706 adjustable version
2006/12/20
Rev. 1.6
Champion Microelectronic Corporation
Page 1