PAM2309
1A Step-Down DC-DC Converter
Features
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General Description
The PAM2309 is a step-down current-mode, DC-
DC converter. At heavy load, the constant-
frequency PWM control performs excellent
stability and transient response. To ensure the
longest battery life in portable applications, the
PA M 2 3 0 9 p r o v i d e s a p o w e r - s a v i n g P u l s e -
Skipping Modulation (PSM) mode to reduce
quiescent current under light load operation to
save power.
The PAM2309 supports a range of input voltages
from 2.5V to 5.5V, allowing the use of a single
Li+/Li-polymer cell, multiple Alkaline/NiMH cell,
USB, and other standard power sources. The
output voltage is adjustable from 0.6V to the input
voltage. All versions employ internal power switch
and synchronous rectifierfor to minimize external
part count and realize high efficiency. During
shutdown, the input is disconnected from the
output and the shutdown current is less than
0.1 μ A. Other key features include under-voltage
lockout to prevent deep battery discharge.
The PAM2309 is available in SOT23-5, DFN2x2 6-
Pin and QFN3x3 16-Pin packages.
Efficiency up to 96%
Only 40 μ A(TYP.) Quiescent Current
Output Current: Up to 1A
Internal Synchronous Rectifier
1.5MHz Switching Frequency
Soft Start
Under-Voltage Lockout
Short Circuit Protection
Thermal Shutdown
5-pin Small SOT23-5, DFN2x2 6-Pin and
QFN3x3 16-Pin Packages
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Pb-Free Package
Applications
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Cellular Phone
Portable Electronics
Wireless Devices
Cordless Phone
Computer Peripherals
Battery Powered Widgets
Electronic Scales
Digital Frame
Typical Application
V
IN
C
IN
10μF
L
VIN
SW
Vo
R1
C
FW
Co
10μF
GND
VOUT/FB
R2
EN
R
1
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V
O
=
0.5
´ ç
1
+
÷
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R
2
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Power Analog Microelectronics
,
Inc
www.poweranalog.com
08/2009 Rev 1.1
1
PAM [ POWER ANALOG MICOELECTRONICS ]
