SC441A Datasheet, PDF (10/20 Pages) Semtech Corporation – High Efficiency Integrated Driver for 4-Strings of 150mA LEDs

SC441A
Pin Descriptions
Pin #
1
2
3
4
Pin Name
IO2
IO1
IOGND
AGND
Pin Function
Provides constant current source to LED string 2.
Provides constant current source to LED string 1.
Constant current source ground.
Analog ground
5
SS
Soft-start pin
6
COMP The output of the internal trans-conductance error amplifier.
7
EN
Enable the device including regulator and LED drivers.
8
IOSET
Current source IO value set pin. By selecting the resistor connected from this pin to GND,
the corresponding maximum current on all 4 strings are set.
9
PWM PWM dimming control pin for LED strings.
10
VOUT Internal pull down current source in over voltage fault. Connect this pin directly to Boost output.
11
FFLAG Power failure signal output with open collector. Held low under normal operation.
12
VIN
Power input voltage pin. Bypassed with capacitors close to the pin.
13
OVPRTN Over-Voltage Protection sense signal return path pin.
14
OVPIN Over-Voltage Protection sense signal input.
15,18
PGND Power ground
16,17
SW
Collector of the internal power switch.
19
IO4
Provides constant current source to LED string 4. Connect to VIN for 3 strings operation.
20
IO3
Provides constant current source to LED string 3.
EDP
Solder to the ground plane of the PCB.
Note: Any unused IO pin should be pulled up to VIN.
EN
STATUS
0
backlight disable
1
backlight enable
Note: When EN = 0; the boost is turned OFF and disabled.
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