CAT32_14 Datasheet, PDF (9/11 Pages) ON Semiconductor – CMOS White LED Driver

CAT32
TYPICAL APPLICATION CIRCUITS
(The application diagrams below are shown for the TSOT−23 packages.)
VIN
L₁ 6.8 mH
D1
6
1
VIN
SW
C1
4.7 mF
CAT32
5
SHDN
3
LED
RSET
2.5 V DC 60.40 kW
DIMMING
CONTROL
4
R_SET
1.50 kW
GND
2
15 mA
C2
2.2 mF
Figure 16. Two LEDs with DC Level Dimming Control
VIN
L_{1 6.8 mH}
D1
85
6
1
VIN
SW
80
C1
4.7 mF
CAT32
5
SHDN
3
LED
C2
75
1 mF
RSET
4
GND
2
15 mA
70
2.5 V DC ^{60.40 kW}
DIMMING
CONTROL
65
R_SET
1.50 kW
60
0
Figure 17. Three LEDs with DC Level Dimming Control
VIN
L₁ 6.8 mH
D1
85
C1
80
4.7 mF
6
1
VIN
SW
75
CAT32
PWM ₅
DIMMING
SHDN
3
LED
C2
70
CONTROL
RSET
GND
15 mA
1 mF
4
2
65
R_SET
1.50 kW
60
0
Figure 19. Four LEDs with PWM Dimming Control
V_IN = 4.2 V
V_IN = 3.0 V
5
10
15
20
LED CURRENT (mA)
Figure 18. Efficiency − Three LEDs
V_IN = 4.2 V
V_IN = 3.0 V
5
10
15
20
LED CURRENT (mA)
Figure 20. Efficiency − Four LEDs
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