PAM2805
3-Modes/3W WLED Driver with 1 or 2 Cell Battery
Features
n
3 Modes Cycling Function:
Bright
Power Off
<5S
Power Off
<5S
Dimming
Blinking
Power Off
<5S
General Descriptio
n
The PAM2805 is a step-up DC-DC WLED driver
with 3 modes cycling function(100%
brightness,25% brightness and 8.5Hz blinking).
The un i qu e 3 mo de s c y cl i n g fu n ct i on ca n
eliminate the needs of extra functional MCU or IC.
The PAM2805 can deliver up to 750mA output
current by setting an external resistor.
The PAM2805 switches at a 1.0MHz constant
frequency, allowing for the use of small value
external inductor and ceramic capacitors.
A low 95mV feedback voltage reduces the power
loss in the Rs for better efficiency. With its internal
2A, 100 mΩ NMOS switch, the device can provide
high efficiency even at heavy load.
The PAM2805 is available in SOT23-6 package.
n
Reset to Bright mode if Power Off time
more than 5S
n
Adjustable Output Current: up to 750mA
n
8.5Hz Blinking Mode
n
Low Start-Up Voltage: 0.9V(Typ.)
n
Low SW on Resis tanc e: 1 00mΩ
n
Over Temperature Protection
n
Over Voltage Protection
n
SOT23-6 Package
n
Pb-Free Package
Applications
n
White LED Torch (Flashlight)
Typical Application
Block Diagram
VOUT
VIN
SW
95mV
Reference
V
OUT
20uF
L
V
IN
10uF
VIN
SW
VOUT
PAM2805
BLK
1uF
GND
FB
Rs
2.2
μ
H
+
A1
-
Comparator
-
Rc
Cc
A2
+
PWM
Logic
FB
Σ
+
-
BLK
Dimming
and
Blinking
Logic
Ramp
Generator
1.0MHz
Oscillator
PGND
ILED=95mV/Rs
Power Analog Microelectronics
,
Inc
www.poweranalog.com
11/2011 Rev1.0
1
PAM [ POWER ANALOG MICOELECTRONICS ]
