LTC3531/

LTC3531-3.3/LTC3531-3

11

3531fb

S I FOR ATIO

APPLICATIO

Table 3. Capacitor Vendor Information

Supplier

Series

Phone

Website

AVX

X5R

(803) 448-9411

www.avxcorp.com

Murata

X5R

USA: (814) 237-1431 www.murata.com

(800) 831-9172

Sanyo

POSCAP (619) 661-6322

www.sanyovideo.com

Taiyo Yuden X5R

(408) 573-4150

www.taiyo-yuden.com

TDK

X5R

(847) 803-6100

www.component.tdk.com

Component Selection

Only three power components are required to

programming resistors are needed for the adjustable

version. The high operating frequency and low peak

currents of the LTC3531 allow the use of low value, low

profile inductors and tiny external ceramic capacitors.

Inductor Selection

For best efficiency, choose an inductor with high frequency

core material, such as ferrite, to reduce core loses. The

inductor should have low DCR (DC resistance) to reduce

inductor current without saturating. A 10μH to 22μH in-

ductor value with a >500mA current rating and <400mΩ

DCR is recommended. For applications where radiated

noise is a concern, a toroidal or shielded inductor can be

used. Table 2 contains a list of inductor manufacturers.

Capacitor Selection

The buck-boost convertor requires two capacitors. Ceramic

X5R types will minimize ESL and ESR while maintaining

should be between 4.7μF and 22μF. A larger output capaci-

tor should be used if lower peak to peak output voltage

ripple is desired. A larger output capacitor will also improve

manufacturers for input and output capacitor selection.

Table 2. Inductor Vendor Information

Supplier

Series

Phone

Website

COEV

DN4835

(800) 227-7040

www.coev.net

Coilcraft

MSS4020

(847) 639-6400

www.coilcraft.com

LPO3310

DS1608

Murata

LQH43CN

USA: (814) 237-1431

www.murata.com

LQH32CN

(800) 831-9172

Sumida

CDRH4D18

USA: (847) 956-0666

www.sumida.com

CDRH3D16/HP

Japan: 81-3-3607-5111

Toko

D312C

(847) 297-0070

www.tokoam.com

D412C

DB320C