CAT660

9

Doc. No. 5000, Rev. U

CAPACITOR SUPPLIERS

The following manufacturers supply low-ESR capacitors:

Manufacturer

Capacitor Type

Phone

WEB

Email

Comments

AVX/Kyocera

TPS/TPS3

843-448-9411

www.avxcorp.com

avx@avxcorp.com

Tantalum

Vishay/Sprague 595

402-563-6866

www.vishay.com

—

Aluminum

Sanyo

MV-AX, UGX

619-661-6835

www.sanyo.com

Svcsales@sanyo.com Aluminum

Nichicon

F55

847-843-7500

www.nichicon-us.com

—

Tantalum

HC/HD

Aluminum

Capacitor manufacturers continually introduce new series and offer different package styles. It is recommended

that before a design is finalized capacitor manufacturers should be surveyed for their latest product offerings.

The effective output impedance of a CAT660 circuit is

approximately:

Rcircuit

≈ Rout 660 + (4 x ESRC1) + ESRC2

CONTROLLING LOSS IN CAT660 APPLICATIONS

There are three primary sources of voltage loss:

1.

Output resistance

VLOSS

Ω = ILOAD x ROUT, where ROUT is

the CAT660 output resistance and ILOAD is

the load current.

2.

Charge pump (C1) capacitor ESR:

VLOSSC1

4 x ESRC1 x ILOAD, where

ESRC1 is the ESR of capacitor C1.

3.

Output or reservoir (C2) capacitor ESR:

VLOSSC2 = ESRC2 x ILOAD, where ESRC2

is the ESR of capacitor C2.

Increasing the value of C2 and/or decreasing its ESR will

reduce noise and ripple.

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