Rainbow Electronics MAX1574 - Manual (Page 8)

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