PAM2305 Datasheet, PDF (1/17 Pages) Power Analog Micoelectronics – 1A Step-Down DC-DC Converters

Features
n Efficiency up to 96%
n Only 40μA(TYP.) Quiescent Current
n Output Current: Up to 1A
n Internal Synchronous Rectifier
n 1.5MHz Switching Frequency
n Soft Start
n Under-Voltage Lockout
n Short Circuit Protection
n Thermal Shutdown
n 5-pin Small SOT23-5, DFN2x2 6-Pin and
QFN3x3 16-Pin Packages
n Pb-Free Package
Applications
n Cellular Phone
n Portable Electronics
n Wireless Devices
n Cordless Phone
n Computer Peripherals
n Battery Powered Widgets
n Electronic Scales
n Digital Frame
PAM2305
1A Step-Down DC-DC Converters
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
PAM2305 provides a power-saving Pulse-
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 0.1μA. 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.
Typical Application
Fixed Output Voltage
V_IN
C_IN
10μF
1 _{VIN SW} 5 ^L
GND
2
VOUT ₄
3 ^{EN /FB}
Vo
Co
10μF
Adjustable Output Voltage
V_IN
C_IN
10μF
1 _VIN
5
SW
GND
4
2 VOUT/FB
3 _EN
L
R1
R2
Vo
C_FW
Co
10μF
VO
=
0.6 ´
æçè_{1 +}
R1
R2
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÷ø
Power Analog Microelectronics,Inc
www.poweranalog.com
1
09/2008 Rev 1.2