Datasheet


SLVS456C − OCTOBER 2003 − REVISED OCTOBER 2004
www.ti.com
11
TYPICAL CHARACTERISTICS
Figure 5
−60
−50
−40
−30
−20
−10
0
10
20
30
40
50
60
V
I
= 12 V
V
O
= 3.3 V
I
O
= 3 A
f
S
= 500 kHz
See Figure 24
G − Gain − dB
f − Frequency − Hz
10 1k 1M10k 100k
18
0
15
0
30
60
12
0
90
−9
0
−1
20
−1
50
−1
80
−6
0
−3
0
0
LOOP RESPONSE
Phase
Gain
Figure 6
−0.2
−0.1
0.0
0.1
0.2
0.0 0.5 1.0 1.5 2.0 2.5 3.0
LOAD REGULATION
See Figure 24
Output Voltage Change − %
I
O
− Output Current − A
V
I
= 12 V
V
I
= 6 V
V
I
= 18 V
Figure 7
−0.10
−0.05
0.00
0.05
0.10
6 8 10 12 14 16 18
LINE REGULATION
See Figure 24
Output Voltage Change − %
V
I
− Input Voltage − V
1.5 A
0 A
3 A
Figure 8
50
55
60
65
70
75
80
85
90
95
100
0.0 0.5 1.0 1.5 2.0 2.5 3.0
EFFICIENCY
vs
OUTPUT CURRENT
Efficiency − %
I
O
− Output Current − A
V
I
= 6 V
V
I
= 18 V
V
O
= 3.3 V
f
S
= 500 kHz
See Figure 24
V
I
= 12 V
Figure 9
V
I
= 12 V, V
O
= 3.3 V, I
O
= 3 A, f
S
= 500 kHz
INPUT RIPPLE VOLTAGE
Amplitude
Time − 1 µs/div
V
I(Ripple)
= 100 mV/div (ac coupled)
V
(PH)
= 5V/divSee Figure 24
Figure 10
OUTPUT RIPPLE VOLTAGE
Amplitude
Time − 1 µs/div
V
O
= 20 mV/div (ac)
V
I
= 12 V, V
O
= 3.3 V, I
O
= 3 A, f
S
= 500 kHz
V
(PH)
= 5 V/divSee Figure 24
Figure 11
PH PIN VOLTAGE
Amplitude
Time − 1 µs/div
V
(LSG)
= 5 V/div
V
I
= 12 V, V
O
= 3.3 V, I
O
= 3 A, f
S
= 500 kHz
V
(PH)
= 5 V/divSee Figure 24
Figure 12
LOAD TRANSIENT RESPONSE
Load Transient Response − mV
Time − 200 µs/div
V
O
= 10 mV/div (ac coupled)
V
I
= 12 V, V
O
= 3.3 V
I
O
= 3 A, f
S
= 500 kHz
See Figure 24
I
O
= 1 A/div
Figure 13
POWER UP
Power Up Waveforms − V
Time − 2 ms/div
V
O
= 2 V/div
See Figure 24
V
I
= 5 V/div
V
(PWRGD)
= 2 V/div