Page 10

March 2001 TOKO, Inc.

TK715xxAS

APPLICATION INFORMATION

INPUT-OUTPUT CAPACITORS

Linear regulators require input and output capacitors in order to maintain regulator loop stability. The output capacitor

should be selected within the Equivalent Series Resistance (ESR) range as shown in the graphs below for stable

operation. The output capacitor C

increase as C

Note: It is very important to check the selected manufacturers electrical characteristics (capacitance and ESR) over

temperature.

Range which can be used:

Range which can be used: V

I

TANTALUM CAP.

³ 0.1 mF (CERAMIC CAP 0.22 mF

+ 2.2

W

Capacitor used for evaluation: V

I

TANTALUM CAP.

³ 0.22 mF (CERAMIC CAP 0.22

mF + 2.2W

V

I

V

I

V

I

ESR

≥ 0.01 Ω

0.68

µF ≤ CL ≤ 4.7 µF or More

ESR

≥ 1.0 Ω

0.1

µF ≤ CL ≤ 0.22 µF or More

MULTI LAYER CERAMIC CAP

I

OUT

(mA)

5.0

1.6

1.5

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

0

20

40

60

80

100

CL = 4.7 µF MLCC or More

CL = 0.68 µF MLCC

C

IN

= 0.1

µF

Stable area is

above the line

UNSTABLE AREA UNDER

AND TO THE LEFT

3.3

µF

2.2

µF

1.0

µF

TANTALUM CAP

I

OUT

(mA)

5.0

1.6

1.5

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

0

20

40

60

80

100

Stable area is

above the line

UNSTABLE AREA UNDER

AND TO THE LEFT

CL = 0.22 µF (TANTALUM) or More

CL = 0.1 µF TANTALUM

0.1

µF

CIN = 0.1 µF