sc4541 Semtech Corporation, sc4541 Datasheet - Page 9

• Manufacturer Part Number: sc4541
• Description: High Frequency Led Driver With Integrated Schottky And Simple Interconnect
• Manufacturer: Semtech Corporation

Pin Descriptions
Block Diagram
MLPD-WL6
VIN
EN
Pin #
1
2
3
4
5
6
T
1
6
200mV
Reference
Bandgap
SOT23-6
1.25V
Pin #
N/A
3
2
1
6
5
4
Error Amplifier
+
-
Thermal Pad
Pin Name
GND
OUT
SW
EN
FB
IN
Rc
Cc
Input supply pin — add a ceramic capacitor between this pin and ground.
Ground pin — connect to external ground plane.
Collector of the internal power transistor — connect this pin to the boost inductor.
Output voltage pin — this pin is the output of the internal Schottky diode. Connect this pin to a
ceramic output (1µF typical) capacitor and current sense resistor.
LED current feedback pin — connect this pin to anode of the topmost LED in the string and
the current sense resistor to set the total current in the LED string(s). LED current is set by :
200/R
Enable and PWM control pin for LED string — pulling this pin logic high enables the device.
Pad for heat sinking purposes — connect to the external ground plane using multiple vias
when using MLPD-UT6 package. Not electrically connected internally. The SOT23-6 does not
have a thermal pad.
Pin Function
SENSE
OVP
(mA), where R
-
+
+
-
PWM
1.25V
Slope
Comp
SENSE
is in Ohms.
2MHz
Osc
+
-
R
S
Q
EN
A = 1
SW
3
Q1
+
-
R
SENSE
SC4541
4
2
5
GND
FB
OUT
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