TAR5S15~TAR5S50

2007-11-01

7

5. Example of Characteristics when Ceramic Capacitor is Used

Shown below is the stable operation area, where the output voltage does not oscillate, evaluated using a

Toshiba evaluation circuit. The equivalent series resistance (ESR) of the output capacitor and output current

determines this area. TAR5Sxx Series devices operate stably even when a ceramic capacitor is used as the

output capacitor.

If a ceramic capacitor is used as the output capacitor and the ripple frequency is 30 kHz or more, the ripple

rejection differs from that when a tantalum capacitor is used. This is shown below.

Toshiba recommend that users check that devices operate stably under the intended conditions of use.

Examples of safe operating area characteristics

Evaluation Circuit for Stable Operating Area

Ripple Rejection Characteristic (f

= 10 kHz~300 kHz)

(TAR5S15) Stable Operating Area

Output current IOUT (mA)

(TAR5S50) Stable Operating Area

(TAR5S28) Stable Operating Area

Output current IOUT (mA)

Output current IOUT (mA)

(TAR5S30) Ripple Rejection – f

Frequency f (Hz)

TAR5S**

GND

Ceramic

+ 1 V

CONTROL

ESR

Ceramic

Capacitors used for evaluation

30

0

10

20

40

70

50

60

Ceramic

2.2

μF

10 k

300 k

100 k

Ceramic 10

μF

Tantalum10

μF

Tantalum 2.2

μF

Tantalum 1

μF

Ceramic

1

μF

@VIN = 4.0 V, CNOISE = 0.01 μF,

CIN = 1 μF, Vripple = 500 mVp-p,

Iout = 10 mA, Ta = 25°C

1000 k

80

40

0.02

0.1

1

10

100

0

20

150

60

120

100

140

@VIN = 2.5 V, CNOISE = 0.01 μF,

CIN = 1 μF, Cout = 1 μF~10 μF,

Ta

= 25°C

Stable Operating Area

80

40

0.02

0.1

1

10

100

020

150

60

120

100

140

@VIN = 6.0 V, CNOISE = 0.01 μF,

CIN = 1 μF, Cout = 1 μF~10 μF,

Ta

= 25°C

Stable Operating Area

80

40

0.02

0.1

1

10

100

0

20

150

60

120

100

140

@VIN = 3.8 V, CNOISE = 0.01 μF,

CIN = 1 μF, Cout = 1 μF~10 μF,

Ta

= 25°C

Stable Operating Area