
180mA, 1x/2x, White LED Charge Pump
in 3mm x 3mm TDFN
C1
0.22 μ F OR 0.47 μ F
CP
CN
2.7V TO 5.5V
C IN
1 μ F
IN
1x/2x REGULATING CHARGE PUMP
ERROR
OUT
C OUT
1 μ F
AMP1
OVD
DIMMING
CONTROL AND
ENABLE
ON
OFF
EN
CONTROL AND
REFERENCE
0.18V
0.6V
CONTROLLED-CURRENT
SELMIN
1.25V
LED1
D1
MIRROR
LED2
D2
ERROR
LED3
D3
AMP2
SET
R SET
MAX1574
GND
Figure 2. Functional Diagram and Typical Application Circuit
Chip Information
0.22 μ F
TRANSISTOR COUNT: 6063
PROCESS: BiCMOS
2.7V TO 5.5V
1 μ F
IN
CP
CN
OUT
1 μ F
MAX1574
GND
LED1
ON/OFF AND
DIMMING
EN
SET
LED2
LED3
Figure 3. Using the MAX1574 to Drive Fewer Than Three LEDs
8
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