CAT32_08 Datasheet, PDF (10/14 Pages) Catalyst Semiconductor – CMOS White LED Driver

CAT32
TYPICAL APPLICATION CIRCUITS
The application diagrams below are shown for the TSOT-23 packages.
Two LEDs with DC Level Dimming Control
L₁
6.8µH
D1
VIN
6
1
VIN
SW
C1
4.7µF
2.5V DC
DIMMING
CONTROL
CAT32
5 _SHDN
LED ³
RSET
4
60.40kΩ
GND
2
R_SET
1.50kΩ
15mA
C2
2.2µF
Three LEDs with DC Level Dimming Control
L₁
6.8µH
D1
VIN
6
1
VIN
SW
C1
4.7µF
2.5V DC
DIMMING
CONTROL
CAT32
5
SHDN
LED ³
RSET
4
60.40kΩ
GND
2
R_SET
1.50kΩ
15mA
Efficiency - Three LEDs
85
V_IN = 4.2V
80
V_IN = 3.0V
75
C2
70
1µF
65
60
0
5
10
15
20
LED CURRENT [mA]
Four LEDs with PWM Dimming Control
L₁
6.8µH
D1
VIN
C1
4.7µF
6
1
VIN
SW
CAT32
PWM
DIMMING
5
SHDN
CONTROL
LED ³
C2
1µF
RSET
GND
15mA
4
2
R_SET
1.50kΩ
Efficiency - Four LEDs
85
V_IN = 4.2V
80
V_IN = 3.0V
75
70
65
60
0
5
10
15
20
LED CURRENT [mA]
Doc. No. MD-5001 Rev. AD
10
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice