lt3590 Linear Technology Corporation, lt3590 Datasheet - Page 8

• Manufacturer Part Number: lt3590
• Description: 48v Buck Mode Led Driver In Sc70 And 2mm X 2mm Dfn
• Manufacturer: Linear Technology Corporation

LT3590
APPLICATIONS INFORMATION
Inductor Selection
A 220μH inductor is recommended for most LT3590 ap-
plications with V
applications with V
effi ciency are major concerns, the inductor should have
low core losses at 850kHz and low DCR (copper wire
resistance). Several manufacturers and inductor series
that meet these criteria are listed in Table 1. The effi ciency
comparison of different inductors is shown in Figure 3.
Table 1. Inductor Manufacturers
VENDOR
Coilcraft
www.coilcraft.com
Sumida
www.sumida.com
Toko
www.tokoam.com
Würth Elektronik
www.we-online.com
Coiltronics
www.cooperet.com
Murata
www.murata.com
8
IN
DO1605
LPS4012
LPS3010
1812FS
MSS5131
CDC4D20
LLQ1608
LLQ2012
WE-PD2
TYPE M
WE-PD2
TYPE L
CTX32C
LQH32M
LQH43M
< 25V and 470μH is recommended for
IN
SERIES
PART
> 25V. Although small size and high
(RELEVANT TO
INDUCTANCE
RANGE (μH)
THIS PART)
100 TO 680
100 TO 680
100 TO 330
100 TO 680
100 TO 390
100 TO 680
100 TO 270
100 TO 680
100 TO 220
100 to 470
100 to 330
100 to 560
100 to 680
92
90
88
86
84
Figure 3. Effi ciency Comparison of Different Inductors
0
V
10 LEDs
FRONT PAGE
APPLICATION
CIRCUIT
IN
= 48V
10
5.4 × 4.2 × 1.8
4.0 × 4.0 × 1.2
3.0 × 3.0 × 0.9
5.1 × 5.1 × 3.1
4.8 × 4.8 × 2.0
5.2 × 5.8 × 4.5
7.0 × 7.8 × 5.0
2.5 × 3.2 × 2.2
3.2 × 2.5 × 2.0
4.5 × 3.2 × 2.0
DIMENSIONS
LED CURRENT (mA)
(mm)
20
30
40
Capacitor Selection
The small size of ceramic capacitors make them ideal
for LT3590 applications. X5R and X7R types are recom-
mended because they retain their capacitance over wider
voltage and temperature ranges than other types such as
Y5V or Z5U. A 1μF input capacitor and a 0.1μF regulator
capacitor are suffi cient for most applications. For the
output capacitor, 1μF is generally recommended, but if
the voltage across the capacitor exceeds 10V, a 0.47μF
capacitor may be used instead. For applications driving
one or two LEDs a 2.2μF output capacitor is needed.
Table 2 shows a list of several ceramic capacitor manufac-
turers. Consult the manufacturers for detailed information
on their entire selection of ceramic parts.
Table 2: Recommended Ceramic Capacitor Manufacturers
Taiyo Yuden
AVX
Murata
Kemet
3590 F03
50
TDK SLF70145-471MR22-PF
MURATA QH32CN471K23
MURATA LQH43CN471K03
COILCRAFT LP06013-474KLB
COILCRAFT 1008PS-474KLB
COILCRAFT LPS4012-474ML
[phone]
www.t-yuden.com
[phone]
www.avxcorp.com
[phone]
www.murata.com
[phone]
www.kemet.com
3590f