PAM2312
1A Step-Down DC-DC Converter
Features
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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 Packages
Pb-Free Package
General Description
The PAM2312 is a step-down current-mode, DC-
DC converter. At heavy load, the constant-
frequency P WM control per for ms exc ellent
stability and transient response. To ensure the
longest battery life in portable applications, the
PA M 2 3 1 2 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 PAM2312 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 PAM2312-
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 1
μ
A. Other key features
include under-voltage lockout to prevent deep
battery discharge.
The PAM2312 is available in SOT23-5 packages.
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
L
VIN SW
GND
VOUT
/FB
Vo
Co
10µF
V
IN
C
IN
10µF
L
VIN
SW
R1
C
FW
Vo
Co
10µF
GND
VOUT/FB
R2
EN
EN
R
1
ö
æ
V
O
=
0.6
´ ç
1
+
÷
è
R
2
ø
Power Analog Microelectronics
,
Inc
www.poweranalog.com
05/2010 Rev1.0
1
PAM [ POWER ANALOG MICOELECTRONICS ]
