www.ti.com

Ceramic Capacitors (Recommended)

Tantalum Capacitors

Capacitor Table

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

APPLICATION INFORMATION (continued)

Above 150 kHz the performance of aluminum electrolytic capacitors becomes less effective. To further improve

the reflected input ripple current or the output transient response. Multilayer ceramic capacitors have very low

ESR and their resonant frequency higher than the bandwidth of the regulator. They can be used to reduce the

reflected ripple current at the input as well as improve the transient response of the output. When used on the

output their combined ESR is not critical as long as the total value of ceramic capacitance does not exceed

300 µF. Also, to prevent the formation of local resonances, do not place more than five identical ceramic

capacitors in parallel with values of 10 µF or greater.

Tantalum type capacitors can be used at both the input and output, and are recommended for applications where

the ambient operating temperature can be less than 0°C. The AVX TPS, Sprague 593D/594/595 and Kemet

T495/T510 capacitor series are suggested over many other tantalum types due to their higher rated surge, power

dissipation, and ripple current capability. As a caution many general purpose tantalum capacitors have

considerably higher ESR, reduced power dissipation and lower ripple current capability. These capacitors are

also less reliable when determining their power dissipation and surge current rating. Tantalum capacitors that do

not have a stated ESR or surge current rating are not recommended for power applications.

When specifying Os-Con and polymer tantalum capacitors for the output, the minimum ESR limit will be

encountered well before the maximum capacitance value is reached.

Table 1 identifies the characteristics of capacitors from a number of vendors with acceptable ESR and ripple

current (rms) ratings. The recommended number of capacitors required at both the input and output buses is

identified for each capacitor type.

This is not an extensive capacitor list. Capacitors from other vendors are available with comparable

specifications. Those listed are for guidance. The RMS ripple current rating and ESR (at 100 kHz) are critical

parameters necessary to insure both optimum regulator performance and long capacitor life.

Table 1. Input/Output Capacitors(1)

Capacitor Characteristics

Quantity

Capacitor Vendor,

Vendor

Working

Max ESR

Max Ripple

Physical

Value

Input

Output

Type/Series (Style)

Part Number

Voltage

at 100 kHz

Current at 85°CSize

(µF)

Bus

Bus

(V)

(Ω)

(Irms) (mA)

(mm)

Panasonic, Aluminum

FC (Radial)

10

470

0.117

555

8×10

1

1

EEUFC1A471

FK (SMD)

25

470

0.080

850

10×10.2

1

1

EEVFK1E471P

FC (SMD)

16

470

0.150

670

10×10.2

1

1

EEVFC1C471P

United Chemi-Con

PXA, Poly-Aluminum (SMD)

6.3

470

0.020

>4100

10×7.7

1

≤2

PXA6.3VC471MJ80TP

PS, Poly-Aluminum (Radial)

6.3

390

0.012

4770

8×11.5

1

≤1(2)

6PS390MH11

PSA, Poly-Aluminum (Radial)

10

470

0.008

5650

8×11,5

1

≤1

PSA10VB470MJ11

LXZ, Aluminum (Radial)

16

470

0.090

760

10×12.5

1

1

LXZ16VB471M10X12LL

Panasonic, Poly-Aluminum

S/SE (SMD)

6.3

180

0.005

4000

7.3×4.3×4.2

2

N/R(3)

EEFSE0J181R

(1) Capacitor Supplier Verification

Please verify availability of capacitors identified in this table. Capacitor suppliers may recommend alternative part numbers because of

limited availability or obsolete products. In some instances, the capacitor product life cycle may be in decline and have short-term

consideration for obsolescence.

RoHS, Lead-free and Material Details

Please consult capacitor suppliers regarding material composition, RoHS status, lead-free status, and manufacturing process

requirements. Component designators or part number deviations can occur when material composition or soldering requirements are

updated.

(2) The total capacitance can be slightly lower than recommended minimum, but is acceptable based on the combined ripple current rating.

(3) This capacitor is not recommended for the VO bus. The capacitor ESR is below the specified minimum for non-ceramic capacitor.

7