TACR156K003S - AVX Corporation - Datasheet.Directory

TACmicrochip

The world’s smallest surface mount

Tantalum capacitor, small enough to

create space providing room for ideas

to grow.

TACmicrochip is a major breakthrough

in miniaturization without reduction in

performance.

It offers you the highest energy store

in an 0603 or 0805 case size; enhanced

high frequency operation through unique

ESR performance with temperature and

voltage stability.

CASE DIMENSIONS: millimeters (inches)

Code EIA W +0.20 (0.008) L +0.25 (0.010) H +0.20 (0.008) t (min.) D (min.)

Code -0.10 (0.004) -0.15 (0.006) -0.10 (0.004)

L0603 0.85 (0.033) 1.6 (0.063) 0.85 (0.033) 0.15 (0.006) 0.70 (0.028)

R0805 1.35 (0.053) 2.0 (0.079) 1.35 (0.053) 0.15 (0.006) 0.90 (0.035)

POLARITY BAND NOT

TO EXCEED CENTER LINE

STANDARD CAPACITANCE RANGE (LETTER DENOTES CASE SIZE)

Capacitance Rated voltage to 85°C

µF 2.0V 3.0V 4.0V 6.3V 10V 16V

0.47 L

0.68 L

1.0 L L L

1.5 L L L

2.2 L L L L 

3.3 L L L L L/R

4.7 L L L L L/R

6.8 L L L R R 

10.0 L L L/R L/R R 

15.0 R R /R R

22.0 R /R /R R

33.0 R R /R 

47.0 R R

68.0 R

•= In Development

NOTE: Terminations are plated 100% Su.

TACmicrochip

TAC

Type

TACmicrochip

Case Code

0603=L

0805=R

225

Capacitance Code

pF code: 1st two

digits represent

significant figures,

3rd digit represents

multiplier (number of

zeros to follow)

Tolerance

K=±10%

M=±20%

003

Rated DC Voltage

002=2Vdc

003=3Vdc

004=4Vdc

006=6.3Vdc

010=10Vdc

016=16Vdc

Packaging

X=8mm 4-1/4"

Tape & Reel

R=7" Tape & Reel

(see page 49)

Additional

characters may be

add for special

requirements

HOW TO ORDER

AVX Case Capacitance Leakage DF ESR

Style Size µF@120Hz µA % Max

(Max) Max @100kHz

2 v @ 85°C

TACL335*002# 0603 3.3 0.5 6 10

TACL475*002# 0603 4.7 0.5 6 10

TACL685*002# 0603 6.8 0.5 6 10

3 v @ 85°C

TACL225*003# 0603 2.2 0.5 6 10

TACL335*003# 0603 3.3 0.5 6 10

TACL475*003# 0603 4.7 0.5 6 10

TACL685*003# 0603 6.8 0.5 10 10

TACL106*003# 0603 10 0.5 10 10

4 v @ 85°C

TACL155*004# 0603 1.5 0.5 6 10

TACL225*004# 0603 2.2 0.5 6 10

TACL335*004# 0603 3.3 0.5 6 10

TACL475*004# 0603 4.7 0.5 6 10

TACL685*004# 0603 6.8 0.5 6 10

6.3 v @ 85°C

TACL105*006# 0603 1.0 0.5 6 10

TACL155*006# 0603 1.5 0.5 6 10

TACL225*006# 0603 2.2 0.5 6 10

TACL335*006# 0603 3.3 0.5 6 10

TACL475*006# 0603 4.7 0.5 6 10

TACL106*006# 0603 10 0.6 10 6

10 v @ 85°C

TACL474*010# 0603 0.47 0.5 6 12

TACL684*010# 0603 0.68 0.5 6 10

TACL105*010# 0603 1.0 0.5 6 10

TACL155*010# 0603 1.5 0.5 6 10

TACL225*010# 0603 2.2 0.5 6 10

TACL335*010# 0603 3.3 0.5 6 10

16 v @ 85°C

TACL105*016# 0603 1.0 0.5 6 10

AVX Case Capacitance Leakage DF ESR

Style Size µF@120Hz µA % Max

(Max) Max @100kHz

2 v @ 85°C

TACR226*002# 0805 22 0.5 8 6

TACR336*002# 0805 33 0.7 8 6

TACR476*002# 0805 47 1.0 10 6

3 v @ 85°C

TACR156*003# 0805 15 0.5 8 6

TACR226*003# 0805 22 0.7 8 6

TACR336*003# 0805 33 1.0 8 6

TACR476*003# 0805 47 1.5 10 6

4 v @ 85°C

TACR106*004# 0805 10 0.5 8 6

TACR156*004# 0805 15 0.6 8 6

TACR226*004# 0805 22 0.9 8 6

TACR336*004# 0805 33 1.3 10 6

6.3 v @ 85°C

TACR685*006# 0805 6.8 0.5 8 6

TACR106*006# 0805 10 0.6 8 6

TACR156*006# 0805 15 0.9 8 6

10 v @ 85°C

TACR475*010# 0805 4.7 0.5 8 6

TACR685*010# 0805 6.8 0.7 8 6

TACR106*010# 0805 10 1.0 8 6

TACR156*010# 0805 15 1.5 8 6

RATINGS AND PART NUMBER REFERENCE

0805 / CASE CODE R0603 / CASE CODE L

All technical data relates to an ambient temperature of +25°C. Capacitance and

DF are measured at 120Hz, 0.5V RMS with a maximum DC bias of 2.2 volts.

DCL is measured at rated voltage after 5 minutes.

*Insert K for ±10% and M for ±20%

#Insert R for 7" reel and S for 13" reel

NOTE: AVX reserves the right to supply a higher voltage rating or tighter

tolerance part in the same case size, to the same reliability standards.

For parametric information on development codes, please contact your

local AVX sales office.

Introduction

AVX Tantalum

AVX’s focus is CUSTOMER satisfaction - customer satisfac-

tion in the broadest sense: product quality, technical support,

product availability and all at a competitive price.

In pursuance of the established goals of our corporate wide

QV2000 program, it is the stated objective of AVX Tantalum

to supply our customers with a world class service in the

manufacturing and supplying of electronic components

which will result in an adequate return on investment.

This world class service shall be defined as consistently

supplying product and services of the highest quality and

reliability.

This should encompass, but not be restricted to all aspects

of the customer supply chain.

In addition any new or changed products, processes or

services will be qualified to established standards of quality

and reliability.

The objectives and guidelines listed above shall be achieved

by the following codes of practice:

1. Continual objective evaluation of customer needs and

expectations for the future and the leverage of all AVX

resources to meet this challenge.

2. By continually fostering and promoting culture of continu-

ous improvement through ongoing training and empowered

participation of employees at all levels of the company.

3. By Continuous Process Improvement using sound engi-

neering principles to enhance existing equipment, material

and processes. This includes the application of the

science of S.P.C. focused on improving the Process

Capability Index, Cpk.

All AVX Tantalum manufacturing locations are approved to

ISO9001/ISO9002 and QS9000 - Automotive Quality

System Requirements.

QUALITY STATEMENTS

APPLICATIONS

2-16 Volt

Low ESR

Low Profile Case

0603 available

Low Failure Rate

High Volumetric Efficiency

Temperature Stability

Stable over Time

50 Volt @ 85°C

33 Volt @ 125°C

Automotive Range

High Reliability

Temperature Stability

QS9000 Approved

Up to 150°C

2-35 Volt

Low ESR

Low Profile Case

0603 available

Low Failure Rate

High Volumetric Efficiency

Temperature Stability

Stable over Time

Introduction

AVX Tantalum

AVX Paignton is the Divisional Headquarters for the Tantalum

division which has manufacturing locations in Paignton in the

UK, Biddeford in Maine, USA, Juarez in Mexico, Lanskroun

in the Czech Republic and El Salvador.

The Division takes its name from the raw material used to

make its main products, Tantalum Capacitors. Tantalum is

an element extracted from ores found alongside tin and

niobium deposits; the major sources of supply are Canada,

Brazil and Australasia.

So for high volume tantalum capacitors with leading edge

technology call us first - AVX your global partner.

The amount of capacitance possible in a tantalum capacitor

is directly related to the type of tantalum powder used to

manufacture the anode.

The graph following shows how the (capacitance) x (voltage)

per gram (CV/g) has steadily increased over time, thus allow-

ing the production of larger and larger capacitances with the

same physical volume. CV/g is the measure used to define

the volumetric efficiency of a powder, a high CV/g means a

higher capacitance from the same volume.

These improvements in the powder have been achieved

through close development with the material suppliers.

AVX Tantalum is committed to driving the available technology

forwards as is clearly identified by the new TACmicrochip

technology and the standard codes under development.

If you have any specific requirements, please contact your

local AVX sales office for details on how AVX Tantalum can

assist you in addressing your future requirements.

TECHNOLOGY TRENDS

1975 1980 1985 1990 1995 2000

Year

CV/g ('000s)

In line with our desire to become the number one supplier in

the world for passive and interconnection components, AVX

is constantly looking forward and innovating.

It is not good enough to market the best products; the

customer must have access to a service system which suits

their needs and benefits their business.

The AVX ‘one stop shopping’ concept is already beneficial

in meeting the needs of major OEMs while worldwide

partnerships with only the premier division of distributors aids

the smaller user.

Helping to market the breadth and depth of our electronic

component line card and support our customers are a

dedicated team of commercial sales people, applications

engineers and product marketing managers. Their qualifica-

tions are hopefully always appropriate to your commercial

need, but as higher levels of technical expertise are required,

access directly to the appropriate department is seamless

and transparent.

Total quality starts and finishes with our customer service,

and where cost and quality are perceived as given quantities

the AVX service invariably has us selected as the preferred

supplier.

Facilities are equipped with instant worldwide computer and

telecommunication links connected to every sales and pro-

duction site worldwide. That ensures that our customers

delivery requirements are consistently met wherever in the

world they may be.

WORKING WITH THE CUSTOMER

- ONE STOP SHOPPING

Tantalum Powder CV/gm

Tantalum capacitors are manufactured from a powder of

pure tantalum metal. The typical particle size is between 2

and 10 µm.

Figure below shows typical powders. Note the very great

difference in particle size between the powder CVs.

4000µFV 20000µFV 50000µFV

Figure 1.

The powder is compressed under high pressure around a

Tantalum wire (known as the Riser Wire) to form a “pellet”.

The riser wire is the anode connection to the capacitor.

This is subsequently vacuum sintered at high temperature

(typically 1400 - 1800°C). This helps to drive off any impuri-

ties within the powder by migration to the surface.

During sintering the powder becomes a sponge like

structure with all the particles interconnected in a huge

lattice.

This structure is of high mechanical strength and density, but

is also highly porous giving a large internal surface area

(see Figure 2).

The larger the surface area the larger the capacitance. Thus

high CV (capacitance/voltage product) powders, which have

a low average particle size, are used for low voltage, high

capacitance parts.

By choosing which powder is used to produce each capac-

itance/voltage rating the surface area can be controlled.

The following example uses a 220µF 10V capacitor to

illustrate the point.

C=orA

where

o

is the dielectric constant of free space

(8.855 x 10-12 Farads/m)

ris the relative dielectric constant for Tantalum

Pentoxide (27)

d is the dielectric thickness in meters

C is the capacitance in Farads

and A is the surface area in meters

Rearranging this equation gives:

A=Cd

or

thus for a 220µF 10V capacitor the surface area is 550

square centimeters, or nearly twice the size of this page.

The dielectric is then formed over all the tantalum surfaces

by the electrochemical process of anodization. To achieve

this, the “pellet” is dipped into a very weak solution of phos-

phoric acid.

The dielectric thickness is controlled by the voltage applied

during the forming process. Initially the power supply is kept

in a constant current mode until the correct thickness of

dielectric has been reached (that is the voltage reaches the

‘forming voltage’), it then switches to constant voltage mode

and the current decays to close to zero.

The chemical equations describing the process are as

follows:

Anode: 2 Ta →2 Ta5+ + 10 e

2 Ta5+ + 10 OH-→Ta2O5+ 5 H2O

Cathode: 10 H2O – 10 e→5H2↑+ 10 OH-

The oxide forms on the surface of the Tantalum but it also

grows into the metal. For each unit of oxide two thirds grows

out and one third grows in. It is for this reason that there is a

limit on the maximum voltage rating of Tantalum capacitors

with present technology powders (see Figure 3).

The dielectric operates under high electrical stress. Consider

a 220µF 10V part:

Formation voltage = Formation Ratio x Working Voltage

= 3.5 x 10

= 35 Volts

Technical Summary and

Application Guidelines

Figure 2. Sintered Tantalum

INTRODUCTION

Technical Summary and

Application Guidelines

The pentoxide (Ta2O5) dielectric grows at a rate of 1.7 x 10-9

m/V

Dielectric thickness (d) = 35 x 1.7 x 10-9

= 0.06 µm

Electric Field strength = Working Voltage / d

= 167 KV/mm

The next stage is the production of the cathode plate. This is

achieved by pyrolysis of Manganese Nitrate into Manganese

Dioxide.

The “pellet” is dipped into an aqueous solution of nitrate and

then baked in an oven at approximately 250°C to produce

the dioxide coat. The chemical equation is:

Mn (NO3)2→Mn O2+ 2NO2↑

This process is repeated several times through varying

specific densities of nitrate to build up a thick coat over

all internal and external surfaces of the “pellet”, as shown in

Figure 4.

The “pellet” is then dipped into graphite and silver to

provide a good connection to the Manganese Dioxide

cathode plate. Electrical contact is established by deposition

of carbon onto the surface of the cathode. The carbon

is then coated with a conductive material to facilitate

connection to the cathode termination (see Figure 5).

Packaging is carried out to meet individual specifications and

customer requirements. This manufacturing technique is

adhered to for the whole range of AVX tantalum capacitors,

which can be sub-divided into four basic groups: Chip /

Resin dipped / Rectangular boxed / Axial.

Further information on the production of Tantalum

Capacitors can be obtained from the technical paper “Basic

Tantalum Technology”, by John Gill, available from your local

AVX representative.

Tantalum

Manganese

Dioxide

Oxide Film

Dielectric

Tantalum

Dielectric

Oxide Film

Anode Manganese

Dioxide Graphite Outer

Silver Layer

Silver

Epoxy

Cathode

Connection

Figure 3. Dielectric Layer

Figure 4. Manganese Dioxide Layer

Figure 5.

Technical Summary and

Application Guidelines

1.1 CAPACITANCE

1.1.1 Rated capacitance (CR).

This is the nominal rated capacitance. For tantalum capaci-

tors it is measured as the capacitance of the equivalent

series circuit at 20°C using a measuring bridge supplied by a

0.5Vpk-pk 120Hz sinusoidal signal, free of harmonics with a

maximum bias of 2.2Vd.c.

1.1.2 Capacitance tolerance.

This is the permissible variation of the actual value of the

capacitance from the rated value. For additional reading,

please consult the AVX technical publication “Capacitance

Tolerances for Solid Tantalum Capacitors”.

1.1.3 Temperature dependence of capacitance.

The capacitance of a tantalum capacitor varies with temper-

ature. This variation itself is dependent to a small extent on

the rated voltage and capacitor size.

1.1.4 Frequency dependence of the capacitance.

The effective capacitance decreases as frequency increases.

Beyond 100KHz the capacitance continues to drop until res-

onance is reached (typically between 0.5 - 5MHz depending

on the rating). Beyond the resonant frequency the device

becomes inductive.

1.2 VOLTAGE

1.2.1 Rated d.c. voltage (VR)

This is the rated d.c. voltage for continuous operation at

85°C.

1.2.2 Category voltage (VC)

This is the maximum voltage that may be applied continu-

ously to a capacitor. It is equal to the rated voltage up to

+85°C, beyond which it is subject to a linear derating, to 2/3

VRat 125°C.

1.2.3 Surge voltage (VS)

This is the highest voltage that may be applied to a capaci-

tor for short periods of time in circuits with minimum series

resistance of 1Kohm. The surge voltage may be applied up

to 10 times in an hour for periods of up to 30 seconds at a

time. The surge voltage must not be used as a parameter in

the design of circuits in which, in the normal course of oper-

ation, the capacitor is periodically charged and discharged.

1.2.4 Effect of surges

The solid Tantalum capacitor has a limited ability to withstand

voltage and current surges. This is in common with all other

electrolytic capacitors and is due to the fact that they oper-

ate under very high electrical stress across the dielectric. For

example a 25 volt capacitor has an Electrical Field of 147

KV/mm when operated at rated voltage.

100

75 85 95 105 115 125

MAXIMUM CATEGORY

VOLTAGE vs. TEMPERATURE

% Rated Voltage

Temperature (°C)

CAPACITANCE vs. FREQUENCY

Capacitance (µF)

100 1000 10000 100000 1000000

Frequency (Hz)

250

200

150

100

% Capacitance

-5

-10

-15

-55 -25 0 25 50 75 100 125

TYPICAL CAPACITANCE vs. TEMPERATURE

Temperature (°C)

85°C125°C

Rated Surge Category Surge

Voltage Voltage Voltage Voltage

(Vdc.) (Vdc.) (Vdc.) (Vdc.)

4 5.2 2.7 3.2

6.3 8 4 5

10 13 7.0 8

16 20 10 12

20 26 13 16

25 32 17 20

35 46 23 28

50 65 33 40

SECTION 1

ELECTRICAL CHARACTERISTICS AND EXPLANATION OF TERMS

TAJE227K010

It is important to ensure that the voltage across the terminals

of the capacitor never exceeds the specified surge voltage

rating.

Solid tantalum capacitors have a self healing ability provided

by the Manganese Dioxide semiconducting layer used as the

negative plate. However, this is limited in low impedance

applications.

In the case of low impedance circuits, the capacitor is likely

to be stressed by current surges. Derating the capacitor by

50% or more increases the reliability of the component. (See

Figure 2 page 45). The “AVX Recommended Derating Table”

(page 46) summarizes voltage rating for use on common

voltage rails, in low impedance applications.

In circuits which undergo rapid charge or discharge a pro-

tective resistor of 1Ω/V is recommended. If this is impossible,

a derating factor of up to 70% should be used.

In such situations a higher voltage may be needed than is

available as a single capacitor. A series combination should

be used to increase the working voltage of the equivalent

capacitor: For example two 22µF 25V parts in series is equiv-

alent to one 11µF 50V part. For further details refer to J.A.

Gill’s paper “Investigation into the effects of connecting

Tantalum capacitors in series”, available from AVX offices

worldwide.

NOTE:

While testing a circuit (e.g. at ICT or functional) it is likely that

the capacitors will be subjected to large voltage and current

transients, which will not be seen in normal use. These con-

ditions should be borne in mind when considering the

capacitor’s rated voltage for use. These can be controlled by

ensuring a correct test resistance is used.

1.2.5 Reverse voltage and Non-Polar operation.

The values quoted are the maximum levels of reverse voltage

which should appear on the capacitors at any time. These

limits are based on the assumption that the capacitors are

polarized in the correct direction for the majority of their

working life. They are intended to cover short term reversals

of polarity such as those occurring during switching tran-

sients of during a minor portion of an impressed waveform.

Continuous application of reverse voltage without normal

polarization will result in a degradation of leakage current. In

conditions under which continuous application of a reverse

voltage could occur two similar capacitors should be used in

a back-to-back configuration with the negative terminations

connected together. Under most conditions this combination

will have a capacitance one half of the nominal capacitance

of either capacitor. Under conditions of isolated pulses or

during the first few cycles, the capacitance may approach

the full nominal value.

The reverse voltage ratings are designed to cover exception-

al conditions of small level excursions into incorrect polarity.

The values quoted are not intended to cover continuous

reverse operation.

The peak reverse voltage applied to the capacitor must not

exceed:

10% of the rated d.c. working voltage to a maximum of

1.0v at 25°C

3% of the rated d.c. working voltage to a maximum of

0.5v at 85°C

1% of the category d.c. working voltage to a maximum of

0.1v at 125°C

1.2.6 Superimposed A.C. Voltage (Vr.m.s.) -

Ripple Voltage.

This is the maximum r.m.s. alternating voltage; superim-

posed on a d.c. voltage, that may be applied to a capacitor.

The sum of the d.c. voltage and peak value of the

super-imposed a.c. voltage must not exceed the category

voltage, Vc.

Full details are given in Section 2.

1.2.7 Forming voltage.

This is the voltage at which the anode oxide is formed. The

thickness of this oxide layer is proportional to the formation

voltage for a tantalum capacitor and is a factor in setting the

rated voltage.

1.3 DISSIPATION FACTOR AND

TANGENT OF LOSS ANGLE (TAN )

1.3.1 Dissipation factor (D.F.).

Dissipation factor is the measurement of the tangent of the

loss angle (tan ) expressed as a percentage. The measure-

ment of DF is carried out using a measuring bridge which

supplies a 0.5Vpk-pk 120Hz sinusoidal signal, free of har-

monics with a maximum bias of 2.2Vdc. The value of DF is

temperature and frequency dependent.

Note: For surface mounted products the maximum allowed

DF values are indicated in the ratings table and it is important

to note that these are the limits met by the component

AFTER soldering onto the substrate.

TAJD336M006

TAJD476M010

TAJD336M016

TAJC685M020

-2

-4

-6

-8

-10

Leakage Current (µA)

-20 0 20 40 60 80 100

Applied Voltage (Volts)

LEAKAGE CURRENT vs. BIAS VOLTAGE

Technical Summary and

Application Guidelines

1.3.2 Tangent of Loss Angle (tan ).

This is a measurement of the energy loss in the capacitor. It

is expressed as tan and is the power loss of the capacitor

divided by its reactive power at a sinusoidal voltage of spec-

ified frequency. Terms also used are power factor, loss factor

and dielectric loss. Cos (90 - ) is the true power factor. The

measurement of tan is carried out using a measuring

bridge which supplies a 0.5Vpk-pk 120Hz sinusoidal signal,

free of harmonics with a maximum bias of 2.2Vdc.

1.3.3 Frequency dependence of Dissipation Factor.

Dissipation Factor increases with frequency as shown in the

typical curves:

Typical DF vs Frequency

1.3.4 Temperature dependence of Dissipation

Factor.

Dissipation factor varies with temperature as the typical curves

show. For maximum limits please refer to ratings tables.

Typical DF vs Temperature

1.4 IMPEDANCE, (Z) AND EQUIVALENT

SERIES RESISTANCE (ESR)

1.4.1 Impedance, Z.

This is the ratio of voltage to current at a specified frequency.

Three factors contribute to the impedance of a tantalum capac-

itor; the resistance of the semiconductor layer; the capacitance

value and the inductance of the electrodes and leads.

At high frequencies the inductance of the leads becomes

a limiting factor. The temperature and frequency behavior

of these three factors of impedance determine the behavior

of the impedance Z. The impedance is measured at 20°C

and 100kHz.

1.4.2 Equivalent Series Resistance, ESR.

Resistance losses occur in all practical forms of capacitors.

These are made up from several different mechanisms,

including resistance in components and contacts, viscous

forces within the dielectric and defects producing bypass

current paths. To express the effect of these losses they are

considered as the ESR of the capacitor. The ESR is frequency

dependent and can be found by using the relationship;

ESR = tan δ

2πfC

Where f is the frequency in Hz, and C is the capacitance in

farads.

The ESR is measured at 20°C and 100kHz.

ESR is one of the contributing factors to impedance, and

at high frequencies (100kHz and above) it becomes the

dominant factor. Thus ESR and impedance become almost

identical, impedance being only marginally higher.

1.4.3 Frequency dependence of Impedance and ESR.

ESR and Impedance both increase with decreasing frequency.

At lower frequencies the values diverge as the extra contri-

butions to impedance (due to the reactance of the capacitor)

become more significant. Beyond 1MHz (and beyond the

resonant point of the capacitor) impedance again increases

due to the inductance of the capacitor.

Typical ESR vs Frequency

Typical Impedance vs Frequency

100

0.1

0.1 1 10

Frequency (kHz)

Impedance Multiplier

100 1000

4.5

3.5

2.5

1.5

0.5

0.1 1 10

ESR Multiplier

Frequency (kHz)

100 1000

1.8

1.7

1.6

1.5

1.4

1.3

1.2

1.1

0.9

0.8

-55 -5 45 95

Temperature (Celcius)

DF Multiplier

0.1

0.1 1 10 100

Frequency (kHz)

DF Multiplier

Technical Summary and

Application Guidelines

1.4.4 Temperature dependence of the Impedance

and ESR.

At 100kHz, impedance and ESR behave identically and

decrease with increasing temperature as the typical curves

show.

Typical 100kHz ESR vs Temperature

1.5 D.C. LEAKAGE CURRENT

1.5.1 Leakage current.

The leakage current is dependent on the voltage applied,

the elapsed time since the voltage was applied and the

component temperature. It is measured at +20°C with the

rated voltage applied. A protective resistance of 1000Ω

is connected in series with the capacitor in the measuring

circuit. Three to five minutes after application of the rated

voltage the leakage current must not exceed the maximum

values indicated in the ratings table. These are based on the

formulae 0.01CV or 0.5µA (whichever is the greater).

Reforming of tantalum capacitors is unnecessary even after

prolonged storage periods without the application of voltage.

1.5.2 Temperature dependence of the leakage

current.

The leakage current increases with higher temperatures,

typical values are shown in the graph. For operation between

85°C and 125°C, the maximum working voltage must be

derated and can be found from the following formula.

Vmax =



1- (T - 85)



x VR volts, where T is the required

125 operating temperature.

LEAKAGE CURRENT vs. TEMPERATURE

1.5.3 Voltage dependence of the leakage current.

The leakage current drops rapidly below the value corre-

sponding to the rated voltage VRwhen reduced voltages are

applied. The effect of voltage derating on the leakage current

is shown in the graph. This will also give a significant increase

in the reliability for any application. See Section 3.1 for

details.

For additional information on Leakage Current, please

consult the AVX technical publication “Analysis of Solid

Tantalum Capacitor Leakage Current” by R. W. Franklin.

1.5.4 Ripple current.

The maximum ripple current allowed is derived from the

power dissipation limits for a given temperature rise above

ambient temperature (please refer to Section 2).

0.1

0.01

020 40 60 80 100

Rated Voltage (VR) %

Leakage Current

ratio I/IVR

LEAKAGE CURRENT vs. RATED VOLTAGE

Typical

Range

-55 -40 -20 0 20 40 60 80 100 +125

0.1

Temperature (°C)

Leakage current

ratio I/IR20

02040

Temperature (Celcius)

Change in ESR

60 80 100 125-20-40

-55

1.8

1.7

1.6

1.5

1.4

1.3

1.2

1.1

0.9

0.8

Technical Summary and

Application Guidelines

Technical Summary and

Application Guidelines

Table I: Power Dissipation Ratings (In Free Air)

TAJ/TPS/CWR11/THJ

TAJ/TPS/CWR11/THJ TAZ/CWR09 TAZ/CWR09

Series Molded Chip Series Molded Chip Series Molded Chip

2.1 RIPPLE RATINGS (A.C.)

In an a.c. application heat is generated within the capacitor

by both the a.c. component of the signal (which will depend

upon the signal form, amplitude and frequency), and by the

d.c. leakage. For practical purposes the second factor is

insignificant. The actual power dissipated in the capacitor is

calculated using the formula:

P = I2 R

and rearranged to I = (P⁄R) .....(Eq. 1)

and substituting P = E2R

where I = rms ripple current, amperes

R = equivalent series resistance, ohms

E = rms ripple voltage, volts

P = power dissipated, watts

Z = impedance, ohms, at frequency under

consideration

Maximum a.c. ripple voltage (Emax).

From the previous equation:

E max = Z (P⁄R) .....(Eq. 2)

Where P is the maximum permissible power dissipated as

listed for the product under consideration (see tables).

However care must be taken to ensure that:

1. The d.c. working voltage of the capacitor must not be

exceeded by the sum of the positive peak of the applied

a.c. voltage and the d.c. bias voltage.

2. The sum of the applied d.c. bias voltage and the negative

peak of the a.c. voltage must not allow a voltage reversal

in excess of the “Reverse Voltage”.

Historical ripple calculations.

Previous ripple current and voltage values were calculated

using an empirically derived power dissipation required to

give a 10°C rise of the capacitors body temperature from

room temperature, usually in free air. These values are shown

in Table I. Equation 1 then allows the maximum ripple current

to be established, and Equation 2, the maximum ripple

voltage. But as has been shown in the AVX article on thermal

management by I. Salisbury, the thermal conductivity of a

Tantalum chip capacitor varies considerably depending upon

how it is mounted.

Case Max. power

size dissipation (W)

A 0.075

B 0.085

C 0.110

D 0.150

E 0.165

R 0.055

S 0.065

T 0.080

V 0.250

W 0.090

Y 0.125

Case Max. power

size dissipation (W)

A 0.050

B 0.070

C 0.075

D 0.080

E 0.090

F 0.100

G 0.125

H 0.150

Temperature correction factor

for ripple current

Temp. °C Factor

+25 1.0

+55 0.95

+85 0.90

+125 0.40

√

SECTION 2

A.C. OPERATION, RIPPLE VOLTAGE AND RIPPLE CURRENT

A piece of equipment was designed which would pass sine

and square wave currents of varying amplitudes through a

biased capacitor. The temperature rise seen on the body for

the capacitor was then measured using an infra-red probe.

This ensured that there was no heat loss through any ther-

mocouple attached to the capacitor’s surface.

Results for the C, D and E case sizes

Several capacitors were tested and the combined results are

shown above. All these capacitors were measured on FR4

board, with no other heatsinking. The ripple was supplied at

various frequencies from 1KHz to 1MHz.

As can be seen in the figure above, the average Pmax value

for the C case capacitors was 0.11 Watts. This is the same

as that quoted in Table I.

The D case capacitors gave an average Pmax value 0.125

Watts. This is lower than the value quoted in the Table I by

0.025 Watts.

The E case capacitors gave an average Pmax of 0.200 Watts

which was much higher than the 0.165 Watts from Table I.

If a typical capacitor’s ESR with frequency is considered, e.g.

figure below, it can be seen that there is variation. Thus for a

set ripple current, the amount of power to be dissipated by

the capacitor will vary with frequency. This is clearly shown in

figure in top of next column, which shows that the surface

temperature of the unit rises less for a given value of ripple

current at 1MHz than at 100KHz.

The graph below shows a typical ESR variation with fre-

quency. Typical ripple current versus temperature rise for

100KHz and 1MHz sine wave inputs.

If I2R is then plotted it can be seen that the two lines are in

fact coincident, as shown in figure below.

Example

A Tantalum capacitor is being used in a filtering application,

where it will be required to handle a 2 Amp peak-to-peak,

200KHz square wave current.

A square wave is the sum of an infinite series of sine waves

at all the odd harmonics of the square waves fundamental

frequency. The equation which relates is:

ISquare = Ipksin (2πƒ) + Ipk sin (6πƒ) + Ipk sin (10πƒ) + Ipk sin (14πƒ) +...

Thus the special components are:

Let us assume the capacitor is a TAJD686M006

Typical ESR measurements would yield.

Thus the total power dissipation would be 0.069 Watts.

From the D case results shown in figure top of previous

column, it can be seen that this power would cause the

capacitors surface temperature to rise by about 5°C.

For additional information, please refer to the AVX technical

publication “Ripple Rating of Tantalum Chip Capacitors” by

R.W. Franklin.

70.00

60.00

50.00

40.00

30.00

20.00

10.00

0.00

0.00 0.05 0.45

0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.50

Temperature Rise (°C)

100KHz

1 MHz

0.00 0.20 0.40 0.60 0.80 1.00 1.20

RMS current (Amps)

Temperature rise (°C)

100KHz

1 MHz

ESR vs. FREQUENCY

(TPSE107M016R0100)

ESR (Ohms)

0.1

0.01100 1000 10000 100000 1000000

Frequency (Hz)

100

00.1 0.2 0.3 0.4 0.5

Power (Watts)

Temperature rise (

oC)

C case

D case

E case

Frequency Typical ESR Power (Watts)

(Ohms) Irms2x ESR

200 KHz 0.120 0.060

600 KHz 0.115 0.006

1 MHz 0.090 0.002

1.4 MHz 0.100 0.001

Frequency Peak-to-peak current RMS current

(Amps) (Amps)

200 KHz 2.000 0.707

600 KHz 0.667 0.236

1 MHz 0.400 0.141

1.4 MHz 0.286 0.101

Technical Summary and

Application Guidelines

The heat generated inside a tantalum capacitor in a.c.

operation comes from the power dissipation due to ripple

current. It is equal to I2R, where I is the rms value of the

current at a given frequency, and R is the ESR at the same

frequency with an additional contribution due to the leakage

current. The heat will be transferred from the outer surface by

conduction. How efficiently it is transferred from this point is

dependent on the thermal management of the board.

The power dissipation ratings given in Section 2.1 are based

on free-air calculations. These ratings can be approached if

efficient heat sinking and/or forced cooling is used.

In practice, in a high density assembly with no specific

thermal management, the power dissipation required to give

a 10°C rise above ambient may be up to a factor of 10

less. In these cases, the actual capacitor temperature should

be established (either by thermocouple probe or infra-red

scanner) and if it is seen to be above this limit it may

be necessary to specify a lower ESR part or a higher

voltage rating.

Please contact application engineering for details or contact

the AVX technical publication entitled “Thermal Management

of Surface Mounted Tantalum Capacitors” by Ian Salisbury.

LEAD FRAME

SOLDER

ENCAPSULANT

COPPER

PRINTED CIRCUIT BOARD

TANTALUM

ANODE

121 C\WATT

73 C\WATT

236 C\WATT

X - RESULTS OF RIPPLE CURRENT TEST - RESIN BODY

TEMPERATURE DEG C

THERMAL IMPEDANCE GRAPH

C CASE SIZE CAPACITOR BODY

140

120

100

00 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4

POWER IN UNIT CASE, DC WATTS

= PCB MAX Cu THERMAL = PCB MIN Cu AIR GAP = CAP IN FREE AIR

Thermal Dissipation from the Mounted Chip

Thermal Impedance Graph with Ripple Current

Technical Summary and

Application Guidelines

2.2 Thermal Management

3.1 STEADY-STATE

Tantalum Dielectric has essentially no wear out mechanism

and in certain circumstances is capable of limited self

healing. However, random failures can occur in operation.

The failure rate of Tantalum capacitors will decrease with time

and not increase as with other electrolytic capacitors and

other electronic components.

Figure 1. Tantalum Reliability Curve

The useful life reliability of the Tantalum capacitor is affected

by three factors. The equation from which the failure rate can

be calculated is:

F = FU x FT x FR x FB

where FU is a correction factor due to operating

voltage/voltage derating

FT is a correction factor due to operating

temperature

FR is a correction factor due to circuit series

resistance

FB is the basic failure rate level. For standard

Tantalum product this is 1%/1000 hours

Base failure rate.

Standard tantalum product conforms to Level M reliability

(i.e., 1%/1000 hrs.) at rated voltage, rated temperature,

and 0.1Ω/volt circuit impedance. This is known as the

base failure rate, FB, which is used for calculating operating

reliability. The effect of varying the operating conditions on

failure rate is shown on this page.

Operating voltage/voltage derating.

If a capacitor with a higher voltage rating than the maximum

line voltage is used, then the operating reliability will be

improved. This is known as voltage derating.

The graph, Figure 2a, shows the relationship between volt-

age derating (the ratio between applied and rated voltage)

and the failure rate. The graph gives the correction factor FU

for any operating voltage.

Figure 2a. Correction factor to failure rate F for voltage

derating of a typical component (60% con. level).

Figure 2b. Gives our recommendation for voltage derating

to be used in typical applications.

Figure 2c. Gives voltage derating recommendations

as a function of circuit impedance.

Recommended Range

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.01 0.1 1.0 10

Circuit Resistance (Ohm/V)

Working Voltage/Rated Voltage

100 1000 10000

Specified Range in

Low Impedance Circuit

Specified Range

in General Circuit

04 6.3 10 16 20 25

Rated Voltage (V)

Operating Voltage (V)

35 50

1.0000

0.1000

0.0100

0.0010

0.0001

Correction Factor

00.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Applied Voltage / Rated Voltage

Infinite Useful Life

Useful life reliability can be altered by voltage

derating, temperature or series resistance

Infant

Mortalities

SECTION 3

RELIABILITY AND CALCULATION OF FAILURE RATE

Technical Summary and

Application Guidelines

Operating Temperature.

If the operating temperature is below the rated temperature

for the capacitor then the operating reliability will be

improved as shown in Figure 3. This graph gives a correction

factor FT for any temperature of operation.

Figure 3: Correction factor to failure rate F for ambient

temperature T for typical component

(60% con. level).

Circuit Impedance.

All solid tantalum capacitors require current limiting

resistance to protect the dielectric from surges. A series

resistor is recommended for this purpose. A lower circuit

impedance may cause an increase in failure rate, especially

at temperatures higher than 20°C. An inductive low imped-

ance circuit may apply voltage surges to the capacitor and

similarly a non-inductive circuit may apply current surges to

the capacitor, causing localized over-heating and failure. The

recommended impedance is 1 Ωper volt. Where this is not

feasible, equivalent voltage derating should be used

(See MIL HANDBOOK 217E). The graph, Figure 4, shows

the correction factor, FR, for increasing series resistance.

Figure 4. Correction factor to failure rate F for series resistance

R on basic failure rate FB for a typical component

(60% con. level).

For circuit impedances below 0.1 ohms per volt, or for any

mission critical application, circuit protection should be con-

sidered. An ideal solution would be to employ an AVX SMT

thin-film fuse in series.

Example calculation

Consider a 12 volt power line. The designer needs about

10µF of capacitance to act as a decoupling capacitor near a

video bandwidth amplifier. Thus the circuit impedance will be

limited only by the output impedance of the board’s power

unit and the track resistance. Let us assume it to be about

2 Ohms minimum, i.e. 0.167 Ohms/Volt. The operating

temperature range is -25°C to +85°C. If a 10µF 16 Volt

capacitor was designed in the operating failure rate would

be as follows.

a) FT = 1.0 @ 85°C

b) FR = 0.85 @ 0.167 Ohms/Volt

c) FU = 0.08 @ applied voltage/rated

voltage = 75%

d) FB = 1%/1000 hours, basic failure rate level

Thus F = 1.0 x 0.85 x 0.08 x 1 = 0.068%/1000 Hours

If the capacitor was changed for a 20 volt capacitor, the

operating failure rate will change as shown.

FU = 0.018 @ applied voltage/rated voltage = 60%

F = 1.0 x 0.85 x 0.018 x 1 = 0.0153%/1000 Hours

3.2 Dynamic.

As stated in Section 1.2.4, the solid Tantalum capacitor has

a limited ability to withstand voltage and current surges.

Such current surges can cause a capacitor to fail. The

expected failure rate cannot be calculated by a simple

formula as in the case of steady-state reliability. The two

parameters under the control of the circuit design engineer

known to reduce the incidence of failures are derating and

series resistance.

The table below summarizes the results of trials carried out

at AVX with a piece of equipment which has very low series

resistance with no voltage derating applied. That is the

capacitor was tested at its rated voltage.

Results of production scale derating experiment

As can clearly be seen from the results of this experiment,

the more derating applied by the user, the less likely the

probability of a surge failure occurring.

It must be remembered that these results were derived from

a highly accelerated surge test machine, and failure rates in

the low ppm are more likely with the end customer.

A commonly held misconception is that the leakage current

of a Tantalum capacitor can predict the number of failures

which will be seen on a surge screen. This can be disproved

by the results of an experiment carried out at AVX on 47µF

10V surface mount capacitors with different leakage

currents. The results are summarized in the table on the fol-

lowing page.

100.0

10.0

0.10

1.0

0.01

Correction Factor

20 30 40 50 60 70 80 90 100 110 120

Temperature

Capacitance Number of 50% derating No derating

and Voltage units tested applied applied

47µF 16V 1,547,587 0.03% 1.1%

100µF 10V 632,876 0.01% 0.5%

22µF 25V 2,256,258 0.05% 0.3%

Circuit resistance FR

ohms/volt

3.0 0.07

2.0 0.1

1.0 0.2

0.8 0.3

0.6 0.4

0.4 0.6

0.2 0.8

0.1 1.0

Technical Summary and

Application Guidelines

So there is an order improvement in the capacitors steady-

state reliability.

Soldering Conditions and Board Attachment.

The soldering temperature and time should be the minimum

for a good connection.

A suitable combination for wavesoldering is 230 - 250°C for

3 - 5 seconds.

For vapor phase or infra-red reflow soldering the profile

below shows allowable and dangerous time/temperature

combinations. The profile refers to the peak reflow tempera-

ture and is designed to ensure that the temperature of

the internal construction of the capacitor does not exceed

220°C. Preheat conditions vary according to the reflow

system used, maximum time and temperature would be 10

minutes at 150°C. Small parametric shifts may be noted

immediately after reflow, components should be allowed to

stabilize at room temperature prior to electrical testing.

Both TAJ and TAZ series are designed for reflow and wave

soldering operations. In addition TAZ is available with gold

terminations compatible with conductive epoxy or gold wire

bonding for hybrid assemblies.

Technical Summary and

Application Guidelines

Dangerous Range

Allowable Range

with Preheat

Allowable Range

with Care

270

260

250

240

230

220

210

200

0 2 4 6 8 10 12

Soldering Time (secs.)

Allowable range of peak temp./time combination for wave soldering

Temperature

Leakage current vs number of surge failures

Again, it must be remembered that these results were

derived from a highly accelerated surge test machine,

and failure rates in the low ppm are more likely with the end

customer.

AVX recommended derating table

For further details on surge in Tantalum capacitors refer

to J.A. Gill’s paper “Surge in solid Tantalum capacitors”,

available from AVX offices worldwide.

An added bonus of increasing the derating applied in a

circuit, to improve the ability of the capacitor to withstand

surge conditions, is that the steady-state reliability is

improved by up to an order. Consider the example of a 6.3

volt capacitor being used on a 5 volt rail.

The steady-state reliability of a Tantalum capacitor is affected

by three parameters; temperature, series resistance and

voltage derating. Assume 40°C operation and 0.1

Ohms/Volt series resistance.

The capacitors reliability will therefore be:

Failure rate = FUx FTx FRx 1%/1000 hours

= 0.15 x 0.1 x 1 x 1%/1000 hours

= 0.015%/1000 hours

If a 10 volt capacitor was used instead, the new scaling factor

would be 0.006, thus the steady-state reliability would be:

Failure rate = FUx FTx FRx 1%/1000 hours

= 0.006 x 0.1 x 1 x 1%/1000 hours

= 6 x 10-4 %/1000 hours

DANGEROUS RANGE

ALLOWABLE

RANGE WITH CARE

RECOMMENDED RANGE

0 15 30 45 60

TIME IN SECONDS

260

250

240

230

220

210

Temperature ( C)

Allowable range of peak temp./time combination for IR reflow

Under the CECC 00 802 International

Specification, AVX Tantalum capacitors

are a Class A component.

The capacitors can therefore be

subjected to one IR reflow, one wave

solder and one soldering iron cycle.

If more aggressive mounting tech-

niques are to be used please consult

AVX Tantalum for guidance.

SECTION 4

APPLICATION GUIDELINES FOR TANTALUM CAPACITORS

Voltage Rail Working Cap Voltage

3.3 6.3

510

10 20

12 25

15 35

≥24 Series Combinations (11)

Number tested Number failed surge

Standard leakage range 10,000 25

0.1 µA to 1µA

Over Catalog limit 10,000 26

5µA to 50µA

Classified Short Circuit 10,000 25

50µA to 500µA

IR REFLOW

WAVE SOLDERING

Recommended Ramp Rate Less than 2°C/sec.

Technical Summary and

Application Guidelines

SECTION 4

APPLICATION GUIDELINES FOR TANTALUM CAPACITORS

Recommended soldering profiles for surface mounting of tantalum capacitors is provided in figure below.

AVX will implement a change to the termination finish on its

TAJ, THJ and TPS series surface mount tantalum capacitors

effective January 1, 2001.

After that date all products manufactured will utilize lead free

terminations.

The termination is compatible with the following lead free sol-

der pastes; SnCu, SnCuAg and SnCuAgBi.

It is also compatible with existing SnPb solder pastes /

systems in use today.

The recommended IR reflow profile is shown below.

The following should be noted by customers changing from

lead based systems to the new lead free pastes.

a) The visual standards used for evaluation of solder joints

will need to be modified as lead free joints are not as bright

as with tin-lead pastes and the fillet may not be as large.

b) Resin color may darken slightly due to the increase in

temperature required for the new pastes.

c) Lead free solder pastes do not allow the same self align-

ment as lead containing systems. Standard mounting

pads are acceptable, but machine set up may need to be

modified.

LEAD FREE PROGRAM

LEAD FREE REFLOW PROFILE

300

250

200

150

100

00 50 100 150 200 250 300

• Pre-heating: 150 ±15C / 60-90s

• Max. Peak Gradient 2.5C/s

• Peak Temperature: 240 ±5C

• Time at >230C: 40s Max.

5.1 Acceleration

98.1m/s2(10g)

5.2 Vibration Severity

10 to 2000Hz, 0.75mm of 98.1m/s2(10g)

5.3 Shock

Trapezoidal Pulse, 98.1m/s2for 6ms.

5.4 Adhesion to Substrate

IEC 384-3. minimum of 5N.

5.5 Resistance to Substrate Bending

The component has compliant leads which reduces

the risk of stress on the capacitor due to substrate

bending.

5.6 Soldering Conditions

Dip soldering is permissible provided the solder bath

temperature is ≤270°C, the solder time < 3 seconds

and the circuit board thickness ≥1.0mm.

5.7 Installation Instructions

The upper temperature limit (maximum capacitor surface

temperature) must not be exceeded even under the

most unfavorable conditions when the capacitor is

installed. This must be considered particularly when it

is positioned near components which radiate heat

strongly (e.g. valves and power transistors).

Furthermore, care must be taken, when bending

the wires, that the bending forces do not strain the

capacitor housing.

5.8 Installation Position

No restriction.

5.9 Soldering Instructions

Fluxes containing acids must not be used.

5.9.1 Guidelines for Surface Mount Footprints

Component footprint and reflow pad design for AVX

capacitors.

The component footprint is defined as the maximum board

area taken up by the terminators. The footprint dimensions

are given by A, B, C and D in the diagram, which corre-

sponds to W, max., A max., S min. and L max. for the com-

ponent. The footprint is symmetric about the center lines.

The dimensions x, y and z should be kept to a minimum

to reduce rotational tendencies while allowing for visual

inspection of the component and its solder fillet.

Dimensions PS (Pad Separation) and PW (Pad Width) are

calculated using dimensions x and z. Dimension y may

vary, depending on whether reflow or wave soldering is to

be performed.

For reflow soldering, dimensions PL (Pad Length), PW (Pad

Width), and PSL (Pad Set Length) have been calculated. For

wave soldering the pad width (PWw) is reduced to less than

the termination width to minimize the amount of solder pick

up while ensuring that a good joint can be produced.

NOTE: These recommendations (also in compliance with EIA) are guidelines

only. With care and control, smaller footprints may be considered for

reflow soldering.

Nominal footprint and pad dimensions for each case size are

given in the following tables:

5.10 PCB Cleaning

Ta chip capacitors are compatible with most PCB board

cleaning systems.

If aqueous cleaning is performed, parts must be allowed

to dry prior to test. In the event ultrasonics are used power

levels should be less than 10 watts per/litre, and care must

be taken to avoid vibrational nodes in the cleaning bath.

PL PS

PSL

SECTION 7

QUALIFICATION APPROVAL STATUS

DESCRIPTION STYLE SPECIFICATION

Surface mount TAJ CECC 30801 - 005 Issue 2

capacitors CECC 30801 - 011 Issue 1

MIL-C-55365/8 (CWR11)

TAZ MIL-C-55365/4 (CWR09)

CASE PSL PL PS PW PWw

TAJ A 4.0 (0.157) 1.4 (0.054) 1.2 (0.047) 1.8 (0.071) 0.9 (0.035)

B 4.0 (0.157) 1.4 (0.054) 1.2 (0.047) 2.8 (0.110) 1.6 (0.063)

C 6.5 (0.256) 2.0 (0.079) 2.5 (0.098) 2.8 (0.110) 1.6 (0.063)

D 8.0 (0.315) 2.0 (0.079) 4.0 (0.157) 3.0 (0.119) 1.7 (0.068)

V 8.3 (0.325) 2.3 (0.090) 3.7 (0.145) 3.7 (0.145) 1.7 (0.068)

E 8.0 (0.315) 2.0 (0.079) 4.0 (0.157) 3.0 (0.119) 1.7 (0.068)

R 2.7 (0.100) 1.0 (0.040) 1.0 (0.040) 1.6 (0.060) 0.8 (0.030)

S 4.0 (0.160) 1.4 (0.050) 1.0 (0.040) 1.8 (0.070) 0.8 (0.030)

T 4.0 (0.160) 1.4 (0.050) 1.0 (0.040) 2.8 (0.110) 0.8 (0.030)

W 6.5 (0.256) 2.0 (0.079) 2.5 (0.098) 2.8 (0.110) 1.6 (0.063)

Y 8.0 (0.315) 2.0 (0.079) 4.0 (0.157) 3.0 (0.119) 1.7 (0.068)

TAC L 2.4 (0.095) 0.7 (0.027) 0.9 (0.035) 1.0 (0.039) -

R 3.0 (0.120) 0.7 (0.027) 1.6 (0.063) 1.5 (0.059) -

TAZ A 3.3 (0.126) 1.4 (0.054) 0.5 (0.020) 2.5 (0.098) 1.0 (0.039)

B 4.5 (0.178) 1.4 (0.054) 1.8 (0.070) 2.5 (0.098) 1.0 (0.039)

D 4.5 (0.178) 1.4 (0.054) 1.8 (0.070) 3.6 (0.143) 2.0 (0.079)

E 5.8 (0.228) 1.4 (0.054) 3.0 (0.120) 3.6 (0.143) 2.2 (0.085)

F 6.3 (0.248) 1.4 (0.054) 3.6 (0.140) 4.5 (0.178) 3.0 (0.119)

G 7.4 (0.293) 1.9 (0.074) 3.7 (0.145) 4.0 (0.157) 2.4 (0.095)

H 8.0 (0.313) 1.9 (0.074) 4.2 (0.165) 5.0 (0.197) 3.4 (0.135)

SECTION 5

MECHANICAL AND THERMAL PROPERTIES OF CAPACITORS

Technical Summary and

Application Guidelines

PAD DIMENSIONS: millimeters (inches)

EPOXY UL RATING OXYGEN INDEX

TAJ UL94 V-0 35%

TPS UL94 V-0 35%

TAZ UL94 V-0 35%

THJ UL94 V-0 35%

SECTION 6

EPOXY FLAMMABILITY

Code Ao Bo K W E F G P P2 Po D D1

A 1.83±0.1 3.57±0.1 1.87±0.1 8±0.3 1.75±0.1 3.5±0.05 0.75 min 4±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1+0.2-0.0

B 3.15±0.1 3.77±0.1 2.22±0.1 8±0.3 1.75±0.1 3.5±0.05 0.75 min 4±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1+0.2-0.0

C 3.45±0.1 6.4±0.1 2.92±0.1 12±0.3 1.75±0.1 5.5±0.05 0.75 min 8±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1.5+0.2-0.0

D 4.48±0.1 7.62±0.1 3.22±0.1 12±0.3 1.75±0.1 5.5±0.05 0.75 min 8±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1.5+0.2-0.0

E 4.50±0.1 7.5±0.1 4.5±0.1 12±0.3 1.75±0.1 5.5±0.05 0.75 min 8±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1.5+0.2-0.0

V 6.43±0.1 7.44±0.1 3.84±0.1 12±0.3 1.75±0.1 5.5±0.05 0.75 min 8±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1.5+0.2-0.0

W 3.57±0.1 6.4±0.1 1.65±0.1 12±0.3 1.75±0.1 5.5±0.05 0.75 min 8±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1.5+0.2-0.0

X 4.67±0.1 7.62±0.1 1.65±0.1 12±0.3 1.75±0.1 5.5±0.05 0.75 min 8±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1.5+0.2-0.0

Y 4.67±0.1 7.62±0.1 2.15±0.1 12±0.3 1.75±0.1 5.5±0.05 0.75 min 8±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1.5+0.2-0.0

R 1.65±0.1 2.45±0.1 1.3±0.1 8±0.3 1.75±0.1 3.5±0.05 0.75 min 4±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1+0.2-0.0

S 1.95±0.1 3.55±0.1 1.3±0.1 8±0.3 1.75±0.1 3.5±0.05 0.75 min 4±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1+0.2-0.0

T 3.20±0.1 3.8±0.1 1.35±0.1 8±0.3 1.75±0.1 3.5±0.05 0.75 min 4±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1+0.2-0.0

TACR 1.65±0.1 2.45±0.1 1.3±0.1 8±0.3 1.75±0.1 3.5±0.05 0.75 min 4±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1+0.2-0.0

TACL 1.10±0.1 2±0.1 1.1±0.1 8±0.3 1.75±0.1 3.5±0.05 0.75 min 4±0.1 2±0.05 4±0.1 1.5+0.2-0.0 1+0.2-0.0

Code Tape A B C W t

R 12mm 180±2.0 50 min 13±0.5 12.4±1.5,-0 1.5±0.5

R 8mm 180±2.0 50 min 13±0.5 8.4±1.5,-0 1.5±0.5

S 12mm 330±2.0 50 min 13±0.5 12.4±1.5,-0 1.5±0.5

S 8mm 330±2.0 50 min 13±0.5 8.4±1.5,-0 1.5±0.5

X 8mm 100±2.0 13±0.5 8.4±1.5,-0 1.5±0.5

TAJ, TPS, THJ & TAC Series

Tape and Reel Packaging

Case Size Tape width P 100mm (4") reel 180mm (7") reel 330mm (13") reel

reference mm mm Suffix Qty. Suffix Qty. Suffix Qty.

A 8 4 R 2000 S 8000

B 8 4 R 2000 S 8000

C 12 8 R 500 S 3000

D 12 8 R 500 S 2500

E 12 8 R 400 S 1500

V 12 8 R 400 S 1500

R 8 4 R 2500 S 10000

S 8 4 R 2500 S 10000

T 8 4 R 2500 S 10000

W 12 8 R 1000 S 5000

Y 12 8 R 1000 S 4000

X 12 8 R 1000 S 5000

TACR 8 4 X 500 R 2500

TACL 8 4 X 500 R 3500

TAPE SPECIFICATION

Tape dimensions comply to EIA 481-1

Dimensions A0and B0of the pocket and

the tape thickness, K, are dependent on

the component size.

Tape materials do not affect component

solderability during storage. Carrier Tape

Thickness <0.4mm.

PLASTIC TAPE DIMENSIONS

+ve capacitor orientation

A0 K

Tape and reel packaging for automatic component placement.

Please enter required Suffix on order. Bulk packaging is not available.

TAJ, TPS AND TAC TAPING SUFFIX TABLE

Cover Tape Dimensions

Thickness: 75±25µm

Width of tape:

5.5mm + 0.2mm (8mm tape)

9.5mm + 0.2mm (12mm tape)

REEL DIMENSIONS

TAJ, THJ & TPS Marking

For TAJ & TPS & THJ, the positive end of body has videcon

readable polarity marking as shown in the diagram. Bodies

are marked by indelible laser marking on top surface with

capacitance value, voltage and date of manufacture and

batch ID number. R case is an exception due to the small size

in which only the voltage and capacitance values are printed.

Voltage Code Rated Voltage

at 85°C

J 6.3

A10

C16

D20

E25

V35

T50

TAJ & TPS - A, B, C, D, E, S, T, V, W, Y AND X CASE:

M 1 5 B3

227 A

AVX LOGO Capacitance Value in pF

227 = 220µF

Rated Voltage Code

A = 10V

2 Digit Batch

ID Number

Week Number

Polarity

Code

(Anode)

Year Code

M = 2000

TAJ - R CASE:

1 0 6

Capacitance Value in pF

106 = 10µF

Rated Voltage Code

J = 6.3V

Polarity

Code

(Anode)

THJ - A, B, C, D AND E CASE:

M 1 5 B4

227 A

AVX LOGO Capacitance Value in pF

227 = 220µF

Rated Voltage Code

A = 10V

2 Digit Batch

ID Number

Week Number

Polarity

Code

(Anode)

Year Code

M = 2000

Year Year Code

1999 L

2000 M

2001 N

2002 P

TAZ, CWR09, CWR11 Series

Tape and Reel Packaging

Solid Tantalum Chip TAZ Tape and reel packaging for automatic component placement.

Please enter required Suffix on order. Bulk packaging is standard.

TAZ TAPING SUFFIX TABLE

Case Size Tape width P 7" (180mm) reel 13" reel (330mm) reel

reference mm mm Suffix Qty. Suffix Qty.

A 8 4 R 2500 S 9000

B 12 4 R 2500 S 9000

D 12 4 R 2500 S 8000

E 12 4 R 2500 S 8000

F 12 8 R 1000 S 3000

G 12 8 R 500 S 2500

H 12 8 R 500 S 2500

Code 8mm Tape 12mm Tape

4±0.1 (0.157±0.004) 4±0.1 (0.157±0.004)

P* or or

8±0.1 (0.315±0.004) 8±0.1 (0.315±0.004)

G 0.75 min (0.03 min)0.75 min (0.03 min)

F 3.5±0.05 (0.138±0.002)5.5±0.05 (0.22±0.002)

E 1.75±0.1 (0.069±0.004)1.75±0.1 (0.069±0.004)

W 8±0.3 (0.315±0.012)12±0.3 (0.472±0.012)

P22±0.05 (0.079±0.002)2±0.05 (0.079±0.002)

P04±0.1 (0.157±0.004)4±0.1 (0.157±0.004)

D 1.5±0.1 (0.059±0.004)1.5±0.1 (0.059±0.004)

-0 (-0) -0 (-0)

D11.0 min (0.039 min)1.5 min (0.059 min)

*See taping suffix tables for actual P dimension (component pitch).

TAPE SPECIFICATION

Tape dimensions comply to EIA RS 481 A

Dimensions A0and B0of the pocket and

the tape thickness, K, are dependent on

the component size.

Tape materials do not affect component

solderability during storage.

Carrier Tape Thickness <0.4mm

Total Tape Thickness — K max

TAZ

Case size Millimeters (Inches)

reference DIM

A 2.0 (0.079)

B 4.0 (0.157)

D 4.0 (0.157)

E 4.0 (0.157)

F 4.0 (0.157)

G 4.0 (0.157)

H 4.0 (0.157)

TAZ, CWR09, CWR11 Series

Tape and Reel Packaging

Waffle Packaging - 2" x 2" hard plastic waffle trays. To order Waffle

packaging use a “W” in part numbers packaging position.

NOTE: Orientation of parts in waffle packs

varies by case size.















12.8mm

minimum

diameter

2 ± 0.5

T ± 1.0

A max

50 min

20.2 min

Maximum

Case Size Quantity

Per Waffle

TAZ A 160

TAZ B 112

TAZ D 88

TAZ E 60

TAZ F 48

TAZ G 50

TAZ H 28

CWR11 A 96

CWR11 B 72

CWR11 C 54

CWR11 D 28

PLASTIC TAPE REEL DIMENSIONS

Standard Dimensions mm

T: 9.5mm (8mm tape)

13.0mm (12mm tape)

A: See page 49

Cover Tape Dimensions

Thickness: 75±25µ

Width of tape:

5.5mm + 0.2mm (8mm tape)

9.5mm + 0.2mm (12mm tape)

Product Safety Information Sheet

Material Data and Handling

This should be read in conjunction with the Product Data

Sheet. Failure to observe the ratings and the information on

this sheet may result in a safety hazard.

1. Material Content

Solid tantalum capacitors do not contain liquid hazardous

materials.

The operating section contains:

Tantalum Graphite/carbon

Tantalum oxide Conducting paint/resins

Manganese dioxide Fluoropolymers (not TAC)

The encapsulation contains:

TAA - solder, metal case, solder coated terminal wires, glass

seal and plastic sleeve

TAC - epoxy molding compound, tin coated terminal pads

TAJ - epoxy molding compound, solder coated terminal pads

TAP - solder, solder coated terminal wires, epoxy dipped resin

THJ - epoxy molding compound, solder coated terminal pads

TPS - epoxy molding compound, solder coated terminal pads

The epoxy resins may contain Antimony trioxide and Bromine

compounds as fire retardants. The capacitors do not contain

PBB or PBBO/PBBE. The solder alloys may contain lead.

2. Physical Form

These capacitors are physically small and are either rectan-

gular with solderable terminal pads, or cylindrical or bead

shaped with solderable terminal wires.

3. Intrinsic Properties

Operating

Solid tantalum capacitors are polarized devices and operate

satisfactorily in the correct d.c. mode. They will withstand a

limited application of reverse voltage as stated in the data

sheets. However, a reverse application of the rated voltage

will result in early short circuit failure and may result in fire or

explosion. Consequential failure of other associated compo-

nents in the circuit e.g. diodes, transformers, etc. may also

occur. When operated in the correct polarity, a long

period of satisfactory operation will be obtained but failure

may occur for any of the following reasons:

• normal failure rate • temperature too high

• surge voltage exceeded • ripple rating exceeded

• reverse voltage exceeded

If this failure mode is a short circuit, the previous conditions

apply. If the adjacent circuit impedance is low, voltage or

current surges may exceed the power handling capability of

the capacitor. For this reason capacitors in circuits of below

3Ω/V should be derated by 50% and precautions taken to

prevent reverse voltage spikes. Where capacitors may be

subjected to fast switched, low impedance source voltages,

the manufacturers advice should be sought to determine the

most suitable capacitors for such applications.

Non-operating

Solid tantalum capacitors contain no liquids or noxious

gases to leak out. However, cracking or damage to the

encapsulation may lead to premature failure due to ingress of

material such as cleaning fluids or to stresses transmitted to

the tantalum anode.

4. Fire Characteristics

Primary

Any component subject to abnormal power dissipation may

• self ignite

• become red hot

• break open or explode emitting flaming or red

hot material, solid, molten or gaseous.

Fumes from burning components will vary in composition

depending on the temperature, and should be considered to

be hazardous, although fumes from a single component in a

well ventilated area are unlikely to cause problems.

Secondary

Induced ignition may occur from an adjacent burning or red

hot component. Epoxy resins used in the manufacture of

capacitors give off noxious fumes when burning as stated

above. Wherever possible, capacitors comply with the

following: BS EN 60065

UL 492.60A/280

LOI (ASTM D2863-70) as stated in the data sheets.

5. Storage

Solid tantalum capacitors exhibit a very low random failure

rate after long periods of storage and apart from this there are

no known modes of failure under normal storage conditions.

All capacitors will withstand any environmental conditions

within their ratings for the periods given in the detail specifica-

tions. Storage for longer periods under high humidity conditions

may affect the leakage current of resin protected capacitors.

Solderability of solder coated surfaces may be affected by

storage of excess of one year under high temperatures (>40°C)

or humidity (>80%RH).

6. Disposal

Incineration of epoxy coated capacitors will cause emission

of noxious fumes and metal cased capacitors may explode

due to build up of internal gas pressure. Disposal by any

other means normally involves no special hazards. Large

quantities may have salvage value.

7. Unsafe Use

Most failures are of a passive nature and do not represent a

safety hazard. A hazard may, however, arise if this failure

causes a dangerous malfunction of the equipment in which

the capacitor is employed. Circuits should be designed to fail

safe under the normal modes of failure. The usual failure

mode is an increase in leakage current or short circuit. Other

possible modes are decrease of capacitance, increase in

dissipation factor (and impedance) or an open-circuit.

Operations outside the ratings quoted in the data sheets

represents unsafe use.

8. Handling

Careless handling of the cut terminal leads could result in

scratches and/or skin punctures. Hands should be washed

after handling solder coated terminals before eating or smoking,

to avoid ingestion of lead. Capacitors must be kept out of the

reach of small children. Care must be taken to discharge

capacitors before handling as capacitors may retain a residual

charge even after equipment in which they are being used has

been switched off. Sparks from the discharge could ignite a

flammable vapor.

Product Safety Information Sheet

Environmental Information

AVX has always sought to minimize the environmental impact

of its manufacturing operations and of its tantalum capaci-

tors supplied to customers throughout the world.

We have a policy of preventing and minimizing waste streams

during manufacture, and recycling materials wherever

possible. We actively avoid or minimize environmentally

hazardous materials in our production processes.

1. Material Content

For customers wishing to assess the environmental impact

of AVX’s capacitors contained in waste electrical and elec-

tronic equipment, the following information is provided:

Surface mount tantalum capacitors contain:

Tantalum and Tantalum oxide

Manganese dioxide

Carbon/graphite

Silver

Nickel-iron alloy or Copper alloy depending on design

(consult factory for details)

Tin-lead alloy plating

Polymers including fluorinated polymers

Epoxide resin encapsulant

The encapsulant is made fire retardant to UL 94 V-0 by the

inclusion of inert mineral filler, antimony trioxide and an

organic bromine compound.

2. AVX capacitors do not contain any Poly

Brominated Biphenyl (PBB) or PBBE/PBBO.

The approximate content of some materials is given in the

table below:

The specific weight of other materials contained in the vari-

ous case sizes is available on written request.

The component packing tape is either recyclable

Polycarbonate or PVC (depending on case size), and the

sealing tape is a laminate of halogen-free polymers. The reels

are recyclable polystyrene, and marked with the recycling

symbol. The reels are over-packed in recyclable fiber board

boxes. None of the packing contains heavy metals.

3. Future Proposals

Lead

TAJ, TPS and THJ series supplied today are electroplated

over the terminal contact area with 90:10 tin:lead alloy.

Although the lead comprises much less than 0.2% of the

component weight, TAC series currently have lead free

(100% tin) terminations. Parts will be converted to 100% tin

in 2001.

4. Fire Retardants

Currently the only known way of supplying a fire retardant

encapsulant which meets all our performance requirements,

is to incorporate antimony trioxide and an organic bromine

compound. These materials are commonly used in many

plastic items in the home and industry. We expect to be able

to offer an alternative fire retardant encapsulant, free of these

materials, by 2004. A combustible encapsulant free of these

materials could be supplied today, but AVX believes that the

health and safety benefits of using these materials to provide

fire retardancy during the life of the product, far outweigh the

possible risks to the environment and human health.

5. Nickel alloy

It is intended that all case sizes will be made with a high

copper alloy termination. Some case sizes are supplied now

with this termination, and other sizes may be available.

Please contact AVX if you prefer this.

6. Recycling

Surface mount tantalum capacitors have a very long service

life with no known wear-out mechanism, and a low failure

rate. However, parts contained in equipment which is of no

further use will have some residual value mainly because of

the tantalum metal contained. This can be recovered and

recycled by specialist companies. The silver and nickel or

copper alloy will also have some value. Please contact AVX if

you require assistance with the disposal of parts. Packaging

can by recycled as described above.

7. Disposal

Surface mount tantalum capacitors do not contain any

liquids and no part of the devices is normally soluble in water

at neutral pH values. Incineration will cause the emission

of noxious fumes and is not recommended except by

specialists. Land fill may be considered for disposal, bearing

in mind the small lead content.

Typical Antimony Organic

Case Weight Lead Trioxide Bromine

Size mg %%Compound

A 25 0.13 1.7 2.5

B 65 0.11 1.4 2.1

C 137 0.04 2.3 3.4

D 330 0.023 1.5 2.2

E 460 0.017 1.2 1.8

Questions & Answers

Some commonly asked questions regarding Tantalum

Capacitors:

Question: If I use several tantalum capacitors in serial/parallel

combinations, how can I ensure equal current and voltage

sharing?

Answer: Connecting two or more capacitors in series

and parallel combinations allows almost any value

and rating to be constructed for use in an application. For

example, a capacitance of more than 60µF is required in a

circuit for stable operation. The working voltage rail is 24

volts dc with a superimposed ripple of 1.5 volts at 120 Hz.

The maximum voltage seen by the capacitor is Vdc +

Vac=25.5V

Applying the 50% derating rule tells us that a 50V

capacitor is required.

Connecting two 25V rated capacitors in series will

give the required capacitance voltage rating, but the

effective capacitance will be halved, so for greater than 60µF,

four such series combinations are required, as shown.

In order to ensure reliable operation, the capacitors should

be connected as shown below to allow current sharing of

the ac noise and ripple signals. This prevents any one

capacitor heating more than its neighbors and thus being

the weak link in the chain.

The two resistors are used to ensure that the leakage

currents of the capacitors does not affect the circuit

reliability, by ensuring that all the capacitors have half

the working voltage across them.

Question: What are the advantages of tantalum over other

capacitor technologies?

Answer:

1. Tantalum capacitors have high volumetric efficiency.

2. Electrical performance over temperature is very

stable.

3. They have a wide operating temperature range -55

degrees C to +125 degrees C.

4. They have better frequency characteristics than

aluminum electrolytics.

5. No wear out mechanism. Because of their construction,

solid tantalum capacitors do not degrade in perfor-

mance or reliability over time.

Question: How does TPS differ from your standard

product?

Answer: TPS has been designed from the initial anode

production stages for power supply applications. Special

manufacturing processes provide the most robust capacitor

dielectric by maximizing the volumetric efficiency of the

package. After manufacturing, parts are conditioned by

being subjected to elevated temperature overvoltage burn in

applied for a minimum of two hours. Parts are monitored on

a 100% basis for their direct current leakage performance at

elevated temperatures. Parts are then subjected to a low

impedance current surge. This current surge is performed on

a 100% basis with each capacitor individually monitored.

At this stage, the capacitor undergoes 100% test for

capacitance, Dissipation Factor, leakage current, and

100 KHz ESR to TPS requirements.

Question: If the part is rated as a 25 volt part and you have

current surged it, why can’t I use it at 25 volts in a low

impedance circuit?

Answer: The high volumetric efficiency obtained using

tantalum technology is accomplished by using an extremely

thin film of tantalum pentoxide as the dielectric. Even

an application of the relatively low voltage of 25 volts will

produce a large field strength as seen by the dielectric. As a

result of this, derating has a significant impact on reliability as

described under the reliability section. The following example

uses a 22 microfarad capacitor rated at 25 volts to illustrate

the point. The equation for determining the amount of

surface area for a capacitor is as follows:

33µF

25V

33µF

25V

16.5µF

50V

➡

66µF

50V

➡

33µF

25V

••

100K

Questions & Answers

C = ( (E) (E°) (A) ) / d

A = ( (C) (d) ) /( (E°)(E) )

A = ( (22 x 10-6) (170 x 10-9) ) / ( (8.85 x 10-12) (27) )

A = 0.015 square meters (150 square centimeters)

Where

C = Capacitance in farads

A = Dielectric (Electrode) Surface Area (m2)

d = Dielectric thickness (Space between dielectric) (m)

E = Dielectric constant (27 for tantalum)

E°= Dielectric Constant relative to a vacuum

(8.855 x 10-12 Farads x m-1)

To compute the field voltage potential felt by the dielectric we

use the following logic.

Dielectric formation potential = Formation Ratio x

Working Voltage

= 4 x 25

Formation Potential = 100 volts

Dielectric (Ta2O5) Thickness (d) is 1.7 x 10-9 Meters Per Volt

d = 0.17 µ meters

Electric Field Strength = Working Voltage / d

= (25 / 0.17 µ meters)

= 147 Kilovolts per

millimeter

= 147 Megavolts

per meter

No matter how pure the raw tantalum powder or the

precision of processing, there will always be impurity sites in

the dielectric. We attempt to stress these sites in the factory

with overvoltage surges, and elevated temperature burn in

so that components will fail in the factory and not in your

product. Unfortunately, within this large area of tantalum

pentoxide, impurity sites will exist in all capacitors.

To minimize the possibility of providing enough activation

energy for these impurity sites to turn from an amorphous

state to a crystalline state that will conduct energy, series

resistance and derating is recommended. By reducing the

electric field within the anode at these sites, the tantalum

capacitor has increased reliability. Tantalums differ from

other electrolytics in that charge transients are carried by

electronic conduction rather than absorption of ions.

Question: What negative transients can Solid Tantalum

Capacitors operate under?

Answer: The reverse voltage ratings are designed to cover

exceptional conditions of small level excursions into incorrect

polarity. The values quoted are not intended to cover contin-

uous reverse operation. The peak reverse voltage applied to

the capacitor must not exceed:

10% of rated DC working voltage to a maximum

of 1 volt at 25°C.

3% of rated DC working voltage to a maximum of

0.5 volt at 85°C.

1% of category DC working voltage to a maximum

of 0.1 volt at 125°C.

Question: I have read that manufacturers recommend a

series resistance of 0.1 ohm per working volt. You suggest

we use 1 ohm per volt in a low impedance circuit. Why?

Answer: We are talking about two very different sets of

circuit conditions for those recommendations. The 0.1 ohm

per volt recommendation is for steady-state conditions. This

level of resistance is used as a basis for the series resistance

variable in a 1% / 1000 hours 60% confidence level

reference. This is what steady-state life tests are based on.

The 1 ohm per volt is recommended for dynamic conditions

which include current in-rush applications such as inputs to

power supply circuits. In many power supply topologies

where the di/dt through the capacitor(s) is limited, (such

as most implementations of buck (current mode), forward

converter, and flyback), the requirement for series resistance

is decreased.

Question: How long is the shelf life for a tantalum capacitor?

Answer: Solid tantalum capacitors have no limitation on

shelf life. The dielectric is stable and no reformation is

required. The only factors that affect future performance of

the capacitors would be high humidity conditions and

extreme storage temperatures. Solderability of solder coated

surfaces may be affected by storage in excess of one year

under temperatures greater than 40°C or humidities greater

than 80% relative humidity. Terminations should be checked

for solderability in the event an oxidation develops on the

solder plating.

Question: Do you recommend the use of tantalum capacitors

on the input side of DC-DC converters?

Answer: No. Typically the input side of a converter is fed

from the voltage sources which are not regulated and are of

nominally low impedance. Examples would be Nickel-Metal-

Hydride batteries, Nickel-Cadmium batteries, etc., whose

internal resistance is typically in the low milliohm range.