Datasheet

TPS79201, TPS79225
TPS79228, TPS79230
SLVS337B – MARCH 2001 – REVISED MAY 2002
www.ti.com
6
TYPICAL CHARACTERISTICS
Figure 10
0
20
40
60
80
100
120
0 0.02 0.04 0.06 0.08 0.1
T
J
= 125°C
T
J
= 25°C
T
J
= –40°C
I
O
= 100 mA
TPS79228
DROPOUT VOLTAGE
vs
OUTPUT CURRENT
– Dropout Voltage – mV
V
DO
I
O
– Output Current – A
Figure 11
0
20
40
60
80
100
120
2.5 3 3.5 4 4.5 5
T
J
= 125°C
T
J
= 25°C
T
J
= –40°C
I
O
= 100 mA
V
I
– Input Voltage – V
TPS79201
DROPOUT VOLTAGE
vs
INPUT VOLTAGE
– Dropout Voltage – mV
V
DO
Figure 12
2.2
2.7
3.2
3.7
4.2
4.7
1.5 2 2.5 3 3.5 4 4.5 5
T
J
= 125°C
T
J
=– 40°C
T
J
= 25°C
V
I
= 3.2 V
C
o
= 10 µF
5.2
Minimum Required Input Voltage – V
MINIMUM REQUIRED INPUT VOLTAGE
vs
OUTPUT VOLTAGE
V
O
– Output Voltage – V
Figure 13
10 100 1 k 10 k
20
50
90
100 k 1 M 10 M
Ripple Rejection – dB
f – Frequency – Hz
TPS79228
RIPPLE REJECTION
vs
FREQUENCY
I
O
= 10 mA
60
0
V
I
= 3.8 V
C
o
= 10 µF
C
(byp)
= 0.01 µF
I
O
= 100 mA
10
30
40
70
80
Figure 14
10 100 1 k 10 k
20
60
100
100 k 1 M 10 M
Ripple Rejection – dB
f – Frequency – Hz
TPS79228
RIPPLE REJECTION
vs
FREQUENCY
V
I
= 3.8 V
C
o
= 1 µF
C
(byp)
= 0.01 µF
I
O
= 10 mA
I
O
= 100 mA
40
70
90
30
50
80
Figure 15
10 100 1 k 10 k
20
60
100
100 k 1 M 10 M
Ripple Rejection – dB
f – Frequency – Hz
TPS79228
RIPPLE REJECTION
vs
FREQUENCY
V
I
= 3.8 V
C
o
= 1 µF
C
(byp)
= 0.1 µF
I
O
= 10 mA
I
O
= 100 mA
40
70
90
30
50
80
Fi
g
ure 16
3
TPS79228
OUTPUT VOLTAGE, ENABLE VOLTAGE
vs
TIME (START-UP)
V
O
t – Time – µs
0604020 80 100 140120 160 180 200
– Output Voltage – V
V
I
= 3.8 V
V
O
= 2.8 V
I
O
= 100 mA
C
o
= 1 µF
T
J
= 25°C
Enable Voltage – V
1
2
0
0
2
C
(byp)
= 0.001 µF
C
(byp)
= 0.0047 µF
C
(byp)
= 0.01 µF
4
Figure 17
20
TPS79228
LINE TRANSIENT RESPONSE
V
O
t – Time – µs
01510520253530 40 45 50
– Output Voltage – mV
I
O
= 100 mA
C
o
= 1 µF
C
(byp)
= 0.01 µF
V
I
– Input Voltage – V
0
4.8
3.8
–20
dv
dt
+
0.4 V
µs
Figure 18
t – Time – µs
TPS79228
LOAD TRANSIENT RESPONSE
0
0 15010050 200 250 350300 400 450
20
0
–20
V
O
Output Voltage – mV
∆
– Change In
100
500
– Output Current – mA
I
O
V
I
= 3.8 V
C
o
= 10 µF
–40
di
dt
+
0.04 A
µs