PAM2305
1A Step-Down DC-DC Converters
Features
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General Description
The PAM2305 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 5 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 PAM2305 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, while the part number suffix PAM2305-
XX indicates pre-set output voltage of 3.3V, 2.8V,
2.5V, 1.8V, 1.5V, 1.2V or adjustable. 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 PAM2305 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
Fixed Output Voltage
Adjustable Output Voltage
V
IN
C
IN
10μF
1
VIN
GND
SW
5
L
Vo
Co
10μF
V
IN
C
IN
10μF
1
VIN
SW
5
L
R1
C
FW
Vo
Co
10μF
2
VOUT
4
/FB
GND
4
2 VOUT/FB
R2
3 EN
3 EN
R
1
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æ
V
O
=
0.6
´ ç
1
+
÷
è
R
2
ø
Power Analog Microelectronics
,
Inc
www.poweranalog.com
09/2008 Rev 1.2
1
PAM [ POWER ANALOG MICOELECTRONICS ]
