Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

how to use tantalum capacitor?

Status
Not open for further replies.

huzuhong525

Junior Member level 2
Joined
Jun 11, 2008
Messages
22
Helped
3
Reputation
6
Reaction score
1
Trophy points
1,283
Location
China
Activity points
1,386
tantalum capacitor polarity

hi ,
I am a new to electric design ,could somebody list how to use tantalum capacitor or tantalum capacitor used where,the difference from MLCC &other capacitor ?

thank you
 

RF-OM

Advanced Member level 2
Joined
Aug 3, 2007
Messages
584
Helped
123
Reputation
246
Reaction score
17
Trophy points
1,298
Location
The Earth
Activity points
5,751
tantalum capacitors polarity

Tantalum capacitors are electrolytic type. They have big capacitance for relatively small size, the best Farad-per-volume-unit ratio and this is the best type of electrolytic caps, but most expensive one. They are kind of low frequency devices. When you use electrolytic caps you need to keep in mind that they are polarized and therefore must be connected according to their polarity. MLCC or Multi-Layer Ceramic Capacitors are high quality caps. They are able to work on high frequencies (depends on dielectric type). They may be very small and use in high frequency electronics, RF and microwave circuits. The major parameters are capacitance, ESR (Equivalent Series Resistance), ESL (Equivalent Series Inductance), SRF (self-resonant frequency), and Q-factor. Capacitance is ability to store an electrical field energy and this is what we need; next two parameters are parasitic. They reduce upper usable frequency of capacitor as well as Q-factor. The latter shows how much energy will lost into cap, but usually Q is not the problem for capacitors. What is important to know it is what the actual capacitance is. For majority of practical applications this parameter can be calculated as Ceff=C/(1-f/SRF)^2. Here f is frequency of interest and SRF is self-resonant frequency from the data sheet. This formula assumes that cap is used well below the SRF. It is easy to see that very often we have much higher capacitance than shown on the cap itself. Even when when we use cap on frequency about half of SRF the effective capacitance Ceff will be 4 times higher than expected.

Best regards,
RF-OM
 

huzuhong525

Junior Member level 2
Joined
Jun 11, 2008
Messages
22
Helped
3
Reputation
6
Reaction score
1
Trophy points
1,283
Location
China
Activity points
1,386
tantalum polarity

Thanks .

In our GPS project ,the audio singal comes through a 100uf tantalum capacitor that is coupling function,may i use MLCC to replace it for coupling ?
 

s.san2006

Newbie level 6
Joined
Mar 30, 2008
Messages
12
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,331
tantalum cap polarity

Similar to an electrolytic cap, but with good reliability, but blows up badly if connected with wrong polarity.
 

svicent

Full Member level 6
Joined
Jul 11, 2001
Messages
322
Helped
32
Reputation
62
Reaction score
7
Trophy points
1,298
Activity points
2,293
smd tantalum capacitor polarity

A major advantage of tantalum capacitors is that they can be packaged in much smaller sizes than aluminium electrolytics. This means that they are better suited to surface mount production and indeed the majority of small surface mount electrolytics are tantalum types. Capacitance values from 0.1μF to 470μF are available.
 

Borber

Advanced Member level 5
Joined
Dec 31, 1999
Messages
1,602
Helped
234
Reputation
470
Reaction score
111
Trophy points
1,343
Location
on third flor
Activity points
11,862
capacitor tantalum polarity

One of the advantages of tantalum over aluminium electrolytes is much smaller leakage current. This is important when capacitor interstage coupling is used.
 

max0412

Full Member level 5
Joined
Oct 26, 2003
Messages
253
Helped
34
Reputation
66
Reaction score
5
Trophy points
1,298
Activity points
1,999
how to use capacitor

Everything you wanted to know about caps.

Code:
http://www.radio-electronics.com/info/data/capacitor/capacitor_types.php
AVX application notes. If your planning on using Tant caps I suggest you read through these notes from AVX.

I used tinyurl to shorten AVX's 232 character url to the page.

Code:
http://tinyurl.com/3ttzys
Particularly

Voltage Derating Rules for Solid Tantalum & Niobium Capacitors

and

Surge in Solid Tantalum Capacitors

and

Ripple Rating of Tantalum Chip Capacitors

and

Increasing Reliability of SMD Tantalum Capacitors in Low Impedance Applications

Most of the notes are worth looking through but those are the minumum.
 

Medini

Newbie level 5
Joined
Jun 19, 2008
Messages
10
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,330
tant caps polarity

Be careful the max voltage change with temperature and they blow easily. If you can, use ceramic or aluminum
 

huzuhong525

Junior Member level 2
Joined
Jun 11, 2008
Messages
22
Helped
3
Reputation
6
Reaction score
1
Trophy points
1,283
Location
China
Activity points
1,386
polarity of tantalum capacitor

Thanks for your kind help ,I got much from you .
 

tyassin

Advanced Member level 1
Joined
Jul 22, 2004
Messages
455
Helped
84
Reputation
166
Reaction score
38
Trophy points
1,308
Activity points
2,929
reliability over voltage tantalum capacitors

Hi

You can also use POSCAP or OS_CON. These are have the same features as Tantalum but are much more robust too surges and over voltage.

Regards
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top