LTC3558
24
3558f
Table 2 shows several inductors that work well with the
LTC3558 buck switching regulator. These inductors offer
a good compromise in current rating, DCR and physical
size. Consult each manufacturer for detailed information
on their entire selection of inductors.
Buck Switching Regulator
Input/Output Capacitor Selection
Low ESR (equivalent series resistance) ceramic capacitors
should be used at switching regulator outputs as well as
the switching regulator input supply. Ceramic capacitor
dielectrics are a compromise between high dielectric
constant and stability versus temperature and versus
DC bias voltage. The X5R/X7R dielectrics offer the best
compromise with high dielectric constant and acceptable
performance over temperature and under bias. Do not
use Y5V dielectrics. A 10μF output capacitor is suffi cient
APPLICATIONS INFORMATION
for most applications. For good transient response and
stability the output capacitor should retain at least 4
μ
F
of capacitance over operating temperature and bias volt-
age. The buck switching regulator input supply should be
bypassed with a 10μF capacitor. Consult manufacturer
for detailed information on their selection and specifi ca-
tions of ceramic capacitors. Many manufacturers now
offer very thin (< 1mm tall) ceramic capacitors ideal for
use in height-restricted designs. Table 3 shows a list of
several ceramic capacitor manufacturers.
Table 3: Recommended Ceramic Capacitor Manufacturers
AVX
(803) 448-9411
www.avxcorp.com
Murata
(714) 852-2001
www.murata.com
Taiyo Yuden
(408) 537-4150
www.t-yuden.com
TDK
(888) 835-6646
www.tdk.com
Table 2. Recommended Inductors for Buck Switching Regulators
INDUCTOR TYPE
L
(μH)
MAX I
DC
(A)
MAX DCR
(m
Ω
)
SIZE IN mm
(L
×
W
×
H)
MANUFACTURER
DE2818C
DE2812C
4.7
4.7
1.25
1.15
72*
130*
3
×
2.8
×
1.8
3
×
2.8
×
1.2
Toko
www.toko.com
CDRH3D16
4.7
0.9
110
4
×
4
×
1.8
Sumida
www.sumida.com
SD3118
SD3112
4.7
4.7
1.3
0.8
162
246
3.1
×
3.1
×
1.8
3.1
×
3.1
×
1.2
Cooper
www.cooperet.com
LPS3015
4.7
1.1
200
3
×
3
×
1.5
Coilcraft
www.coilcraft.com
*Typical DCR
