Ultra-Efficient Charge Pumps for
Six White/RGB LEDs in 3mm x 3mm Thin QFN
7/MAX648
C3
C2
1μF
1μF
C1P
C1N C2P
C2N
TP7
V
IN
2.7V TO 5.5V
IN
NEG
EP
INVERTING
CHARGE PUMP
C1
1μF
C4
1μF
GND
SEL
MIN
1MHz
OSCILATOR
CURRENT
REGULATOR
V
IN
LED1
LED2
LED3
LED4
LED5
LED6
V
(ENA)
DD
2
I C OR
BIAS
CURRENT
SOURCE
CONTROL
SCL (ENB)
SDA (ENC)
SERIAL PULSE
INTERFACE
AND CONTROL
CURRENT
REGULATOR
THERMAL
SHUTDOWN
CURRENT
REGULATOR
CURRENT
REGULATOR
MAX8647
MAX8648
CURRENT
REGULATOR
CURRENT
( ) ARE FOR THE MAX8648
REGULATOR
Figure 1. Block Diagram and Application Circuit
The MAX8648 is shutdown when all three EN_ are held
low for 4ms or longer. In shutdown, NEG is pulled to
GND with a 10kΩ internal resistor.
Shutdown Mode
The MAX8647 is shutdown when all LEDs are turned off
2
2
through the I C port. In shutdown, the I C port is still
active and ready to receive a command.
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9
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
