PAM2804
1A Step-Down Constant Current, High Efficiency LED Driver
Features
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Efficiency up to 93%
180
μ
A(TYP.) Quiescent Current
Output Current: Up to 1A
Internal Synchronous Rectifier
1.5MHz Switching Frequency
Soft Start
Under-Voltage Lockout
Short LED Protection
Open LED Protection
Thermal Shutdown
5-pin Small SOT23-5 Packages
Pb-Free Package
General Description
The PAM2804 is a step-down constant current
LED driver. When the input voltage down to lower
than LED forward voltage, then PAM2804 run into
LDO mode.
The PAM2804 supports a range of input voltages
from 2.5V to 6.0V, allowing the use of a single
Li+/Li-polymer cell, 3AA or 4AA cell, USB, and
other standard power sources.
The FB voltage is only 0.1V to achieve high
efficiency.
PAM2804 employ internal power switch and
synchronous rectifier 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 of the
Li+ battery.
.
Applications
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3AA or 4AA Batteries Powered Flashlight
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1 Cell Li-Ion Battery Powered Flashlight
Typical Application
1 Cell Li-Ion Battery
3AA or 4AA Batteries
V
IN
C
IN
10µF
L
4.7
µH
VIN
GND
SW
1~5W
WLED
FB
Rs
Co
10µF
EN
ILED =0.1/Rs
Power Analog Microelectronics
,
Inc
www.poweranalog.com
10/2010 Rev1.0
1
PAM [ POWER ANALOG MICOELECTRONICS ]
