Datasheet

LTC3537
15
3537fd
APPLICATIONS INFORMATION
Table 1: Recommended Inductors
VENDOR PART/STYLE
Coilcraft
[phone]
www.coilcraft.com
LPO4815
LPS4012, LPS4018
MSS5131
MSS4020
MOS6020
ME3220
DS1605, DO1608
Coiltronics
www.cooperet.com
SD10, SD12, SD14, SD18,
SD20,
SD52, SD3114, SD3118
FDK
[phone]
www.fdk.com
MIP3226D4R7M,
MIP3226D3R3M
MIPF2520D4R7
MIPWT3226D3R0
Murata
[phone]
www.murata.com
LQH43C
LQH32C (-53 series)
301015
Sumida
[phone]
www.sumida.com
CDRH5D18
CDRH2D14
CDRH3D16
CDRH3D11
CR43
CMD4D06-4R7MC
CMD4D06-3R3MC
Taiyo-Yuden
www.t-yuden.com
NP03SB
NR3015T
NR3012T
TDK
[phone]
www.component.tdk.com
VLP
VLF, VLCF
Toko
[phone]
www.tokoam.com
D412C
D518LC
D52LC
D62LCB
Wurth
[phone]
www.we-online.com
WE-TPC Type S, M
Output and Input Capacitor Selection
Low ESR (equivalent series resistance) capacitors should
be used to minimize the output voltage ripple. Multilayer
ceramic capacitors are an excellent choice as they have
extremely low ESR and are available in small footprints.
A 4.7µF to 10µF output capacitor is suffi cient for most
boost applications. Larger values up to 22µF may be used
to obtain extremely low output voltage ripple and improve
transient response. X5R and X7R dielectric materials are
preferred for their ability to maintain capacitance over
wide voltage and temperature ranges. Y5V types should
not be used.
The internal loop compensation of the LTC3537 is designed
to be stable with a minimum output capacitor value of
4.7µF when in PWM mode on the boost regulator and
1µF or greater on the LDO regulator. Although ceramic
capacitors are recommended, low ESR tantalum capaci-
tors may be used as well. For the LDO, see Figures 2 and
3 for output capacitor value and ESR requirements. To
reduce Burst Mode boost output voltage ripple, 10µF is
recommended.
Figure 2. LDO Regulator Output Capacitance vs ESR
Figure 3. LDO Regulator Minimum Output Capacitance
vs V
INL
/V
OLDO
CAPACITANCE (µF)
ESR ()
3537 F02
1.6
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0.0
1 10 100
REGION OF
OPERATION
V
INL
/V
OLDO
1
MINIMUM OUTPUT CAPACITANCE (µF)
5.0
4.5
3.5
3.0
2.5
2.0
1.0
4.0
1.5
0.5
0.0
436
3537 F03
725