Datasheet

TPS54680
SLVS429B − OCTOBER 2002 − REVISED OCTOBER 2005
www.ti.com
12
PERFORMANCE GRAPHS
Figure 12
60
65
70
75
80
85
90
95
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6
I
O
− Output Current − A
Efficiency − %
EFFICIENCY
vs
OUTPUT CURRENT
V
O
= 1.8 V
V
O
= 1.2 V
V
O
= 0.9 V
V
I
= 3.3 V,
F
S
= 700 kHz,
V
O
= 0.9 V, 1.8 V and 2.5 V
Fi
g
ure 13
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6
0.20
0.15
0.10
0.05
0
−0.05
−0.10
−0.15
−0.20
V
O
= 1.8 V
V
O
= 1.2 V
V
O
= 0.9 V
T
A
= 25°C,
V
I
= 3.3 V,
F
S
= 700 kHz,
V
O
= 0.9 V, 1.2 V and 1.8 V
Load Regulation − %
LOAD REGULATION
vs
OUTPUT CURRENT
I
O
− Output Current − A
Fi
g
ure 14
−0.20
−0.15
−0.10
−0.05
0
0.05
0.10
0.15
0.20
3 3.5 4 4.5 5 5.5 6
I
O
= 6 A
I
O
= 0 A
T
A
= 25°C,
F
S
= 700 kHz,
V
O
= 1.8 V
V
I
− Input Voltage − V
Line Regulation − %
LINE REGULATION
vs
INPUT VOLTAGE
Figure 15
−60
−50
−40
−30
−20
−10
0
10
20
30
40
50
60
−180
−150
−120
−90
−60
−30
0
30
60
90
120
150
180
Phase
Gain
f − Frequency − Hz
Gain − dB
LOOP RESPONSE
Phase − Degrees
V
I
= 5 V,
I
O
= 0 A,
f
S
= 700 kHz
100 1 k 10 k 100 k 1 M
Fi
g
ure 16
25
35
45
55
65
75
85
95
105
115
125
012345678
Ambient Temperature −
AMBIENT TEMPERATURE
vs
LOAD CURRENT
C
°
I
O
− Output Current − A
T
J
= 125°C
f
s
= 700 kHz
V
I
= 3.3 V
V
I
= 5 V
Safe Operating Area
(1)
Fi
g
ure 17
OUTPUT AND INPUT RIPPLE
t − Time − 1 µs/div
Input Ripple − 100 mV/div
Output Ripple − 20 mV/div
Phase Pin − 2 V/div
Figure 18
t − Time −20 µs/div
LOAD TRANSIENT RESPONSE
− Output Voltage −100 mV/div
V
O
Load Current 2A/div
V
I
= 5 V,
V
O
= 1.8 V
Figure 19
t − Time − 500 µs/div
− Output Voltage −1 V/div
STARTUP TIMING
V
O
Power Good − 5 V/div
V
I
= 5 V
f
s
= 700 kHz
I/O
CORE
PWRGD(I/O)
PWRGD(CORE)
Figure 20
t − Time −20 µs/div
POWER DOWN TIMING
− Output Voltage −1 V/div
V
O
Power Good − 5 V/div
I/O
CORE
PWRGD(I/O)
PWRGD(CORE)
(1)
Safe operating area is applicable to the test board conditions in the Dissipation Ratings