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Designing for Very Fast Load Transients

PTH12060W/L

SLTS217D–MAY 2003–REVISED OCTOBER 2005

APPLICATION INFORMATION (continued)

The transient response of the dc/dc converter is characterized using a load transient with a di/dt of 1 A/µs. The

typical voltage deviation for this load transient is given in the data sheet specification table using the optional

value of output capacitance. As the di/dt of a transient is increased, the response of a converter's regulation

circuit ultimately depends on its output capacitor decoupling network. This is an inherent limitation with any dc/dc

converter once the speed of the transient exceeds its bandwidth capability. If the target application specifies a

higher di/dt or lower voltage deviation, the requirement is met with additional output capacitor decoupling. In

these cases, special attention must be paid to the type, value, and ESR of the capacitors selected.

If the transient performance requirements exceed that specified in this data sheet, or the total amount of load

capacitance is above 3,000 µF, the selection of output capacitors becomes more important.

Capacitor Characteristics

Quantity

Max Ripple

Capacitor Vendor,

Working

Max ESR

Vendor Number

Value

Current at

Physical Size

Input

Output

Type/Series (Style)

Voltage

at 100 kHz

(µF)

85°C (Irms)

(mm)

Bus

Bus

(V)

(Ω)

(mA)

Panasonic, Aluminum

25

560

0.065

1205

12,5 × 15

1

1

EEUFC1E561S

FC (Radial)

25

1000

0.060

1100

12,5 × 13,5

1

1

EEVFK1E102Q

FK (SMD)

35

680

0.060

1100

12,5 × 13,5

1

1

EEVFK1V681Q

United Chemi-Con

PS, Poly-Aluminum (Radial)

16

330

0.0014

5050

10 × 12,5

2

≤2

16PS330MJ12

LXZ, Aluminum

16

680

0.068

1050

10 × 16

1

1

LXZ16VB681M10X16L

L

PXA, Poly-Aluminum (SMD)

16

330

0.014

5050

10 × 12,2

2

≤2

PXA16VC331MJ12

Nichicon Aluminum PM

25

560

0.060

1060

12,5 × 15

1

1

UPM1E561MHH6

(Radial)

HD (Radial)

16

680

0.038

1430

10 × 16

1

1

UHD1C681MHR

PM (Radial)

35

560

0.048

1360

16 × 15

1

1

UPM1V561MHH6

Panasonic, Poly-Aluminum:

S/SE (SMD)

6.3

180

0.005

4000

7,3 × 4,3 × 4,2

EEFSE0J181R

Sanyo

TPE, ps-Ccap (SMD)

10

330

0.025

3000

7,3 × 5,7

≤4

10TPE330M

SEPC, Os-con (Radial)

16

470

0.010

>9700

10 × 13

2

≤1

16SEPC470M

SVP, Os-con (SMD)

16

330

0.016

4700

11 × 12

2

≤3

16SVP330M

AVX

TPS, Tantalum (SMD)

10

470

0.045

>1723

TPSE477M019R0045

7,3 × 5,7 × 4,1

TPS, Tantalum (SMD)

10

330

0.045

>1723

2

TPSE337M019R0045

Kemet

T520, Poly-Tantalum (SMD)

10

330

0.040

1800

T520X337M010AS

T530, Tantalum/Organic

10

330

0.015

>3800

≤2

T53X337M010AS

4,3 × 7,3 × 4,0

6.3

470

0.012

4200

T530X477M0061S

(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) N/R – Not recommended. The capacitor voltage rating does not meet the minimum operating limits.

(3) The voltage rating of this capacitor only allows it to be used for output voltages that are equal to or less than 5.1 V.

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