SGM3142 Datasheet, PDF (9/14 Pages) SG Micro Corp – Driver with Low Dropout Current Source

SGM3142
6-Channel Charge Pump White LED Driver
with Low Dropout Current Source
TYPICAL APPLICATION CIRCUITS
C1
C2
1µF
1µF
VBattery
+
6
7
10
11
C1P C1N C2P C2N
14
VIN
16
LED1
1
LED2
CIN
9
VOUT
4
1μF
COUT
1μF
SGM3142 LED3 5
LED4
LED5 ²
EN/SET
15
EN/SET
GND
LED6 ³
12
RB
RB
RB
RB
Resistor R is optional
RB
RB
Resistor R is optional
Figure 3. Driving Two Groups of Paralleled White LED's
C1
C2
1µF
1µF
VBattery
+
6
7
10
11
C1P C1N C2P C2N
14
VIN
16
LED1
1
LED2
CIN
9
VOUT
4
1μF
COUT
1μF
SGM3142 LED3 5
LED4
LED5 ²
EN/SET
15
EN/SET
GND
LED6 ³
12
RB
RB
RB
RB
RB
RB
Photo Flash LED
Resistor R is optional
In some applications, white LED forward voltages (VF) can vary significantly. Ballast resistors between the LED cathodes and ground
are recommended for balancing the forward voltage differences. The ballast resistor value may be approximated by the following
equation:
R_B

V_SOURCE
I_F
 V_F
Figure 4. Driving High Current Photo-Flash LED
SG Micro Corp
9
www.sg-micro.com