sc4541 Semtech Corporation, sc4541 Datasheet - Page 12

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

PCB Layout Considerations
Poor layout can degrade the performance of the DC-DC
converter and can be a contributory factor in EMI prob-
lems, ground bounce, thermal issues, and resistive
voltage losses. Poor regulation and instability can result.
A typical application schematic is shown in Figure 1. A
typical PCB layout is shown in Figure 4.
Applications Information ( continued)
85%
80%
75%
70%
65%
60%
55%
50%
0
5Vin, 10uH(A915AY-100M)
3
5
Efficiency Boost_Iout
C2: MURATA GRM188R7YA105K(1μF/ X7R/ 35V/ 0603)
LED1 to 6: Everlight 12-21C/T3D-CP1Q2B12Y/2C
VIN (5V)
C3: MURATA GRM188R71C105K(1μF/ X7R/ 16V/ 0603)
L1: MURATA LQH3NPN100NM0 (10μH/ 550mA/ 3x3x1.4(mm)
8
10μH
L1
Figure 1 — Typical Application Schematic, Boost Topology
10
Iout(mA)
13
C3
1μF
16V
15
18
U1
IN
GND
SW
3S1P
4S1P
5S1P
6S1P
7S1P
8S1P
SC4541
10KΩ
R5
20
EDP
OUT
EN
FB
The following design rules are recommended:
•
•
82%
80%
78%
76%
74%
72%
70%
Place the inductor and filter capacitors as close
to the device as possible and use short, wide
traces between the power components.
Use a ground plane to further reduce noise
interference on sensitive circuit nodes.
8
10uH(A915AY-100M)
1μF
35V
C2
10
PWM(300Hz, 3.3V)
12
Efficiency Boost_Vout
10Ω
R1
14
16
Vout(V)
V
OUT
LED3
LED4
LED1
LED2
LED5
LED6
18
20
22
24
5Vin
3.6Vin
26
12