TAR5S15U~TAR5S50U
5. Examples of Performance Curves When Ceramic Capacitors Are Used
The stable operating area (SOA) is an area where the output voltage does not go into oscillation. The
following figures represent the SOA obtained using an evaluation circuit shown below. The SOA is determined
by the equivalent series resistance (ESR) of the output capacitor and the output current. The TAR5SxxU
provide stable operation even when a ceramic capacitor is used as the output capacitor.
If the ripple frequency is 30 kHz or greater, the ripple rejection characteristics differ, depending on the type
of the output capacitor (ceramic or tantalum) as shown by the bottom figure on this page.
It is recommended to verify that TAR5SxxU operate properly under the intended conditions of use.
Examples of Safe Operating Area Characteristics
(TAR5S15U) Stable Operating Area
(TAR5S50U) Stable Operating Area
100
10
1
100
10
1
Stable Operating Area
Stable Operating Area
@V = 2.5 V, C
= 0.01 μF,
= 1 μF to 10 μF,
@V = 6.0 V, C
= 0.01 μF,
= 1 μF to 10 μF,
IN NOISE
IN NOISE
0.1
0.1
C
IN
= 1 μF, C
C
= 1 μF, C
OUT
IN
OUT
100
Ta = 25°C
Ta = 25°C
0.02
0.02
0
20
40
60
80
100
120
140150
0
20
40
60
80
120
140150
Output current
I
(mA)
Output current
I
(mA)
OUT
OUT
(TAR5S28U) Stable Operating Area
100
10
1
Circuit for Stable Operating Area Evaluation
CONTROL
C
= 0.01 μF
NOISE
TAR5S**U
C
OUT
Ceramic
Stable Operating Area
GND
R
OUT
V
= V
OUT
+ 1 V
C
IN
IN
Ceramic
ESR
@V = 3.8 V, C
= 0.01 μF,
= 1 μF to 10 μF,
IN NOISE
0.1
C
IN
= 1 μF, C
OUT
Capacitors used for evaluation
Ta = 25°C
C
C
: Murata GRM40B105K
IN
0.02
: Murata GRM40B105K / GRM40B106K
OUT
0
20
40
60
80
100
120
140150
Output current
I
(mA)
OUT
Ripple Rejection Characteristic (f = 10 kHz to 300 kHz)
(TAR5S30U) Ripple Rejection – f
70
Ceramic 10 μF
Tantalum10 μF
60
Ceramic
2.2 μF
50
40
30
20
10
0
Ceramic
1 μF
Tantalum 2.2 μF
Tantalum 1 μF
@V = 4.0 V, C
IN NOISE
= 0.01 μF,
C
IN
= 1 μF, V = 500 mV
p-p
,
Ripple
I
= 10 mA, Ta = 25°C
OUT
10 k
100 k
300 k
1000 k
Frequency
f
(Hz)
7
2009-01-21