LTC3531EDD#TRPBF Linear Technology, LTC3531EDD#TRPBF Datasheet - Page 11

• Manufacturer Part Number: LTC3531EDD#TRPBF
• Description: IC DC/DC CONV 200MA 8-DFN
• Manufacturer: Linear Technology
• Type: Step-Down (Buck), Step-Up (Boost)r

Specifications of LTC3531EDD#TRPBF

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 2 ~ 5 V
• Current - Output: 200mA
• Voltage - Input: 1.8 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-DFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Frequency - Switching: -

APPLICATIO
Component Selection
Only three power components are required to
complete the design of the buck-boost converter, V
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
profi le inductors and tiny external ceramic capacitors.
Inductor Selection
For best effi ciency, 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
the I
inductor current without saturating. A 10μH to 22μH in-
Table 2. Inductor Vendor Information
Supplier
COEV
Coilcraft
Murata
Sumida
Toko
2
R losses, and must be able to handle the peak
Series
DN4835
MSS4020
LPO3310
DS1608
LQH43CN
LQH32CN
CDRH4D18
CDRH3D16/HP
D312C
D412C
DB320C
U
S I FOR ATIO
Phone
[phone]
[phone]
USA: [phone]
[phone]
USA: [phone]
Japan: 81-3-3607-5111
[phone]
U
W
Website
www.coev.net
www.coilcraft.com
www.murata.com
www.sumida.com
www.tokoam.com
U
OUT
Table 3. Capacitor Vendor Information
Supplier
AVX
Murata
Sanyo
Taiyo Yuden X5R
TDK
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
capacitance at rated voltage over temperature. The V
capacitor should be at least 2.2μF. The V
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
load regulation on V
manufacturers for input and output capacitor selection.
LTC3531-3.3/LTC3531-3
Series
X5R
X5R
POSCAP [phone]
X5R
Phone
[phone]
USA: [phone] www.murata.com
[phone]
[phone]
[phone]
OUT
. See Table 3 for a list of capacitor
Website
www.avxcorp.com
www.sanyovideo.com
www.taiyo-yuden.com
www.component.tdk.com
LTC3531/
OUT
capacitor
11
3531fb
IN