Datasheet

TPS79201, TPS79225
TPS79228, TPS79230
SLVS337B – MARCH 2001 – REVISED MAY 2002
www.ti.com
5
TYPICAL CHARACTERISTICS
Figure 1
2.796
2.797
2.799
2.8
2.801
2.802
2.803
0 20406080100
I
O
– Output Current – mA
TPS79228
OUTPUT VOLTAGE
vs
OUTPUT CURRENT
V
I
= 3.8 V
C
o
= 10 µF
T
J
= 25° C
– Output Voltage – V
V
O
Figure 2
2.76
2.77
2.78
2.79
2.8
2.81
2.82
–40 –25 –10 5 20 35 50 65 80 95 110 125
T
J
– Junction Temperature – °C
TPS79228
OUTPUT VOLTAGE
vs
JUNCTION TEMPERATURE
– Output Voltage – V
V
O
I
O
= 100 mA
I
O
= 1 mA
V
I
= 3.8 V
C
o
= 10 µF
Figure 3
100
120
140
160
180
200
220
240
260
–40 –25–10 5 20 35 50 65 80 95 110 125
T
J
– Junction Temperature – °C
TPS79228
GROUND CURRENT
vs
JUNCTION TEMPERATURE
Ground Current – Aµ
I
O
= 1 mA
V
I
= 3.8 V
C
o
= 10 µF
I
O
= 100 mA
Figure 4
f – Frequency – Hz
1k 10k 100k
I
O
= 1 mA
V
I
= 3.8 V
C
o
= 1 µF
C
(byp)
= 0.1 µF
100
I
O
= 100 mA
TPS79228
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
0
0.05
0.1
0.15
0.2
0.25
0.3
V/ HzOutput Spectral Noise Density –
µ
Figure 5
f – Frequency – Hz
1k 10k 100k
I
O
= 1 mA
100
I
O
= 100 mA
Output Spectral Noise Density –
TPS79228
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
V
I
= 3.8 V
C
o
= 10 µF
C
(byp)
= 0.1 µF
0
0.05
0.1
0.15
0.2
0.25
0.3
V/ Hz
µ
Figure 6
f – Frequency – Hz
1k 10k 100k100
V/ HzOutput Spectral Noise Density –
TPS79228
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
V
I
= 3.8 V
I
O
= 100 mA
C
o
= 10 µF
C
(byp)
= 0.1 µF
C
(byp)
= 0.001 µF
µ
C
(byp)
= 0.0047 µF
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
C
(byp)
= 0.01 µF
0.001 0.01 0.1
RMS – Root Mean Squared Output Noise –
TPS79228
ROOT MEAN SQUARED OUTPUT NOISE
vs
BYPASS CAPACITANCE
(RMS)
Vµ
C
(byp)
– Bypass Capacitance – µF
0
10
20
30
40
50
60
Figure 7
V
I
= 3.8 V
V
O
= 2.8 V
I
o
= 100 mA
C
o
= 10 µF
BW = 100 Hz to 100
kHz
Figure 8
100 1 M10 1 k
f – Frequency – Hz
10 k
– Output Impedance –Z
o
Ω
TPS79228
OUTPUT IMPEDANCE
vs
FREQUENCY
100 k
I
O
= 1 mA
0
0.5
1
1.5
2
2.5
0
I
O
= 100 mA
10 M
V
I
= 3.8 V
C
o
= 10 µF
T
J
= 25° C
Figure 9
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
–40 –25 –10 5 20 35 50 65 80 95 110 125
I
O
= 100 mA
I
O
= 10 mA
V
I
= 2.7 V
C
o
= 10 µF
T
J
– Junction Temperature – °C
– Dropout Voltage – V
V
DO
TPS79228
DROPOUT VOLTAGE
vs
JUNCTION TEMPERATURE