LTC3526L-2_15 Datasheet, PDF (11/16 Pages) Linear Technology – 550mA 2MHz Synchronous Step-Up DC/DC Converters

LTC3526L-2/LTC3526LB-2
Applications Information
inductor current without saturating. Molded chokes and
some chip inductors usually do not have enough core
area to support the peak inductor current of 750mA seen
on the LTC3526L-2/LTC3526LB-2. To minimize radiated
noise, use a shielded inductor. See Table 1 for suggested
components and suppliers.
Table 1. Recommended Inductors
VENDOR
PART/STYLE
Coilcraft
[phone]
www.coilcraft.com
LPO4815
LPS4012,
LPS3314
MSS4020
ME3220
Coiltronics
www.cooperet.com
SD10, SD12, SD3114, SD3118
FDK
[phone]
www.fdk.com
MIP3226D
MIPF2520D
MIPWT3226D
MIPSZ2012D
MIPS2520D
Murata
[phone]
www.murata.com
LQH3NP
LQH32P
LQM2MPN
Sumida
[phone]
www.sumida.com
CDRH2D14
CDRH2D11
CDRH3D11
Taiyo-Yuden
www.t-yuden.com
NR3010T
NR3015T
NR3012T
TDK
[phone]
www.component.tdk.com
VLP
VLF, VLCF
Toko
[phone]
www.tokoam.com
D412C
Würth
[phone]
www.we-online.com
WE-TPC type S, M, TH, XS
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 sufficient for most ap-
plications. Larger values 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 LTC3526L-2/
LTC3526LB-2 are designed to be stable with output ca-
pacitor values of 4.7µF or greater (without the need for
any external series resistor). Although ceramic capacitors
are recommended, low ESR tantalum capacitors may be
used as well.
A small ceramic capacitor in parallel with a larger tantalum
capacitor may be used in demanding applications that have
large load transients. Another method of improving the
transient response is to add a small feed-forward capacitor
across the top resistor of the feedback divider (from V_OUT
to FB). A typical value of 22pF will generally suffice.
Low ESR input capacitors reduce input switching noise
and reduce the peak current drawn from the battery. It
follows that ceramic capacitors are also a good choice
for input decoupling and should be located as close as
possible to the device. A 2.2µF input capacitor is sufficient
for most applications, although larger values may be
used without limitations. Table 2 shows a list of several
ceramic capacitor manufacturers. Consult the manufactur-
ers directly for detailed information on their selection of
ceramic capacitors.
Table 2. Capacitor Vendor Information
SUPPLIER
PHONE
WEBSITE
AVX
[phone]
www.avxcorp.com
Murata
[phone]
www.murata.com
Taiyo-Yuden [phone]
www.t-yuden.com
TDK
[phone]
www.component.tdk.com
Samsung
[phone]
www.sem.samsung.com
3526lb2fa
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