and voltage characteristics. Y5V capacitors should not

be used as their temperature coefficients make them

unsuitable for this application. Attention should be paid to

the DC voltage characteristics of the ceramic capacitors

to be used for both input and output. Parts with different

case sizes can vary significantly. For example a 22μF

X5R 0805 capacitor with 3.6V DC applied could have a

capacitance as low as 12μF. When a 1206 size part is

used, the capacitance is approximately 20μF. Table 3 lists

the manufacturers of recommended capacitor options.

Table 3 — Recommended Capacitors

Manufacturer/Part #

Value

(μF)

Rated

Voltage

(VDC)

Temperature

Characteristic

Case Size

Murata

GRM21BR60J226ME39L

22

6.3

X5R

0805

Murata

GRM422X5R226

K16H533

22

16

X5R

1210

Murata

GRM188R60J106

MKE19

10

6.3

X5R

0603

TDK

C2012X5R0J106K

10

6.3

X5R

0603

Note: Where PSAVE operation is required, 22μF must be used for C

Feed-Forward Compensation Capacitor

A small 10pf compensation capacitor, C

to ensure correct operation. This capacitor should

be connected directly across feedback resistor R

Capacitors with X7R or X5R ceramic dielectric are

strongly recommended for their superior temperature

characteristics.

Applications Information (Cont.)

10

© 2007 Semtech Corp.

www.semtech.com

SC196

PRELIMINARY

POWER MANAGEMENT