Datasheet

TPS79015, TPS79018, TPS79025, TPS79028, TPS79030
ULTRALOW-POWER LOW-NOISE 50-mA
LOW-DROPOUT LINEAR REGULATORS
SLVS299B – SEPTEMBER 2000 – REVISED MAY 2001
8
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
100 1k 10k 100k
f – Frequency – Hz
V
I
= 4 V
C
o
= 10 µF
C
(byp)
= 0.1 µF
TPS79030
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
I
O
= 50 mA
0
100
200
300
400
500
600
700
I
O
= 1 mA
nV/ HzOutput Spectral Noise Density –
Figure 9 Figure 10
0
200
400
600
800
1000
1200
1400
1600
1800
100 1k 10k 100k
C
(byp)
= 0.001 µF
C
(byp)
= 0.01 µF
C
(byp)
= 0.1 µF
f – Frequency – Hz
TPS79030
OUTPUT SPECTRAL NOISE DENSITY
vs
FREQUENCY
nV/ HzOutput Spectral Noise Density –
V
I
= 4 V
I
O
= 50 mA
C
o
= 10 µF
150
100
50
0
0.00001 0.0001 0.001 0.01
RMS – Root Mean Squared Output Noise –
200
250
ROOT MEAN SQUARED OUTPUT NOISE
vs
BYPASS CAPACITANCE
300
0.1 1
(RMS)
Vµ
C
(bypass)
– Bypass Capacitance – µF
V
O
= 3 V
V
O
= 1.5 V
Figure 11
C
o
= 10 µF
Figure 12
100 1M10 1k
f – Frequency – Hz
10k
– Output Impedance –Z
o
Ω
OUTPUT IMPEDANCE
vs
FREQUENCY
0
1.6
1
2
0.2
1.4
0.4
1.8
0.6
1.2
0.8
100k
V
I
= 4 V
C
o
= 10 µF
T
J
= 25°C
I
O
= 50 mA
I
O
= 1 mA