Dual High-Efficiency PWM Step-Down DC-DC Coverter
PAM2308
Features
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Efficiency up to 96%
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Only 40μA(Typ. per Channel) Quiescent
Current
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Output Current: Up to 1A per Channel
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Internal Synchronous Rectifier
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1.5MHz Switching Frequency
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Soft Start
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Under-Voltage Lockout
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Short Circuit Protection
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Thermal Shutdown
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Small 10L WDFN 3x3
Packages
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Pb-Free Package and RoHS Compliant
General Description
The PAM2308 is a dual 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 8 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.
The PAM2308 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 dual
output voltages are available for 3.3V, 2.8V, 2.5V,
1.8V, 1.5V, 1.2V or adjustable. All versions
employ internal power switch and synchronous
rectifier for 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.
Applications
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Cellular Phone
Portable Electronics
Personal Information Appliances
Wireless and DSL Modems
MP3 Players
Typical Application
L1
V
OUT1
C
OUT1
10μF
C
Fw1
100nF
R11
1
EN1
FB1
PAM2308
LX1
VIN1
GND
10
8
9
C
IN1
4. μF
7
V
IN1
R12
2
R22
4
C
IN2
4.
7μF
V
IN2
GND
VIN2
LX2
L2
3
5
FB2 7
6
EN2
R21
C
FW2
100pF
V
OUT2
C
OUT2
10μF
V
OUTx
=
V
REF
1
+
Rx1
Rx2
Figure 1. Adjustable Voltage Regulator
(
)
Power Analog Microelectronics
,
Inc
www.poweranalog.com
1
07/2008 Rev 1.0
PAM [ POWER ANALOG MICOELECTRONICS ]
