PAM2805 Datasheet, PDF (1/9 Pages) Power Analog Micoelectronics – 3-Modes/3W WLED Driver with 1 or 2 Cell Battery

PAM2805
3-Modes/3W WLED Driver with 1 or 2 Cell Battery
Features
n 3 Modes Cycling Function:
Power Off
Power Off
Bright ^<5S Dimming ^<5S Blinking
Power Off
<5S
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)
General Description
The PAM2805 is a step-up DC-DC WLED driver
with 3 modes cycling function(100%
brightness,25% brightness and 8.5Hz blinking).
The unique 3 modes cycling function can
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.
Typical Application
VIN
10uF
1uF
L
2.2 μH
VIN
SW
VOUT
PAM2805
BLK
FB
GND
ILED=95mV/Rs
20uF
Block Diagram
VOUT
Rs
95mV
Reference
+
A1
-
FB
BLK
Dimming
and
Blinking
Logic
VOUT VIN
Comparator
-
Rc A2
+
Cc
PWM
Logic
Σ
Ramp
Generator
SW
+
-
1.0MHz
Oscillator
PGND
Power Analog Microelectronics, Inc
www.poweranalog.com
1
11/2011 Rev1.0