sc441c Semtech Corporation, sc441c Datasheet - Page 17

• Manufacturer Part Number: sc441c
• Description: High Efficiency Integrated Driver For 4-strings Of 150ma Leds
• Manufacturer: Semtech Corporation

SC441C
Applications Information (continued)
Layout Guidelines
The SC441C contains a boost converter and the place-
ments of the power components outside the SC441C
should follow the layout guidelines of a general boost
converter. The evaluation application circuit on page 17
will be used as an example. C2 and C3 are input decou-
pling capacitor for SC441C VIN pin and main power input.
C2,C3 should be placed as close as possible to the VIN pin
to achieve the best decoupling performance.
To minimize the switching noise, The switching loop
formed by input decoupling capacitors, internal switch,
output Schottky diode and output capacitors must be
minimized. The LED current programming resistor(R6),
compensation network (R9,C5,C7) and soft start capaci-
tor (C6) should be placed as close as possible to SC441C.
The C14~C17 are decoupling capacitors for LED cur-
rent source which prevent IO pins from noise influence.
C14~C17 should be placed close to each corresponding
IO pin.
Use an isolated local AGND plane underneath the con-
troller and tie it to the negative side of output capacitor
through R14 for better noise immunity.
17
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