Datasheet
Loop Characteristics
2-12
2.7 Loop Characteristics
The TPS54x80EVM-228 loop response characteristics are shown in
Figure 2-14 and Figure 2-15. Gain and phase plots are shown at 3.3 V for
TPS54680 and at 5 V for TPS54680 and TPS54880 regulators.
Figure 2-14. Measured Loop Response, TPS54680, V
I
= 3.3 V, V
O
= 1.8 V
-60
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
100 1 k 10 k 100 k 1 M
-180
-150
-120
-90
-60
-30
0
30
60
90
120
150
180
Gain
Phase
V
I
= 3.3 V,
F
S
= 700 kHz,
I
O
= 0 A
Gain - dB
f - Frequency - Hz
TPS54680-228
FREQUENCY RESPONSE
Phase - Degrees
Figure 2-15. Measured Loop Response, TPS54680 and TPS54880, V
I
= 5 V, V
O
= 1.8 V
-60
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
100 1 k 10 k 100 k 1 M
-180
-150
-120
-90
-60
-30
0
30
60
90
120
150
180
Gain
Phase
V
I
= 5 V,
F
S
= 700 kHz,
I
O
= 0 A
Gain - dB
f - Frequency - Hz
TPS54880-228
FREQUENCY RESPONSE
Phase - Degrees