PAM2701
4-Channel Regulated Charge Pump White LED Driver
Features
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Description
The PAM2701 is a 4-channel charge pump white
LED driver, capable of driving up to 4 LEDs in
parallel. The device operates in either 1x mode or
1.5x fractional mode, and it can switch from 1x
mode to 1.5x mode automatically when the input
voltage decreased. Its internal 4 current sink
regulators ensure both the LED current matching
and the brightness uniformity. The LED current
can be programmed by an external resistor, R
SET
,
connected between the RSET pin and ground.
LED current of up to 30mA are supported by the
input supply voltage over a range of 2.7V to 5.5V,
making the device optimized for Li-Ion battery
applications.
The PAM2701 has a fixed switching frequency of
1MHz, allowing the use of very small value
ceramic capacitors. The enable input pin allows
the device to be set in shutdown mode, and the
current consumption is reduced to less than 1μA.
LED dimming can be done by several methods
including using a DC voltage to set the RSET pin
current, adding a switched resistor in parallel with
R
SET,
or applying a PWM signal to CTRx pin or EN
pin.
Peak Efficiency: 90%
Individual Current Regulation
3-bit Digital Output Control
Two modes of operation:1x and 1.5x
Current Matching with a Max Tolerance
of 3%
Output Current up to 30mA per LED
Total LED Current up to 4*30mA=120mA
Fixed Frequency of 1MHz
Open LED Protection
Space Saving Package QFN 3mmx3mm
and QFN 4mmx4mm
Pb-Free Package
Applications
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Cellular Phones
LED Backlighting
LCD Modules
Handheld Devices
Digital Cameras
PDAs
PMPs
MP3 Players
Typical Application
1μF
1μF
8
7
EN
V
IN
C
IN
1μF Control 0
Control 1
Control 2
R
SET
24kΩ
C1
+
VIN
9
11
10
C2
-
C1
-
C2
+
6
Co
1μF
VOUT
1
EN
PAM2701
2
3
4
5
CTR0
CTR1
CTR2
RSET
GND
LED1
LED2
LED3
LED4
16
15
14
13
20mA
12
Power Analog Microelectronics
,
Inc
www.poweranalog.com
09/2008 Rev 1.3
1
PAM [ POWER ANALOG MICOELECTRONICS ]
