Data Sheet

ADPL42010A

analog.com

Rev. 0

19 of 28

Ceramic Capacitors

Extra consideration must be given to the use of ceramic capacitors. Ceramic capacitors are manufactured with a

variety of dielectrics, each with different behavior over temperature and applied voltage. The most common

dielectrics used are Z5U, Y5V, X5R, and X7R. The Z5U and Y5V dielectrics are good for providing high capacitances in

a small package, but exhibit strong voltage and temperature coefficients, as shown in Figure 31 and Figure 32. When

used with a 5V regulator, a 10µF Y5V capacitor can exhibit an effective value as low as 1µF to 2µF over the operating

temperature range. The X5R and X7R dielectrics result in more stable characteristics and are more suitable for use as

the output capacitor. The X7R type has better stability across temperature, while the X5R is less expensive and is

available in higher values.

Voltage and temperature coefficients are not the only sources of problems. Some ceramic capacitors have a

piezoelectric response. A piezoelectric device generates voltage across its terminals due to mechanical stress, similar

to the way a piezoelectric accelerometer or microphone works. For a ceramic capacitor, the stress can be induced

by vibrations in the system or thermal transients.

Figure 31. Ceramic Capacitor DC Bias Characteristics

Figure 32. Ceramic Capacitor Temperature Characteristics

DC BIAS VOLTAGE (V)

20

0

4

8

10

2

6

12

14

16

X5R

Y5V

BOTH CAPACITORS ARE 16V,

1210 CASE SIZE, 10ΜF

0

–20

–40

–60

–80

–100

TEMPERATURE (°C)

–50

40

25

75

–25

0

50

100

125

Y5V

X5R

BOTH CAPACITORS ARE 16V,

1210 CASE SIZE, 10µF

20

0

–20

–40

–60

–80

–100