Datasheet

Closing the loop A5973AD
20/41 Doc ID 13958 Rev 7
Example:
Considering R
C
= 1.8 kΩ, C
C
= 68nF and C
P
= 330 pF, the poles and zeroes of A
0
are:
F
P1
= 2.9 Hz
F
P2
= 265 kHz
F
Z1
= 1.3 kHz
If L = 12 µH, C
OUT
= 330 µF and ESR = 55 mΩ, the poles and zeroes of A
LC
become:
F
PLC
= 2.5 kHz
F
ZESR
= 8.7 kHz
Finally R
1
= 5.6 kΩ and R
2
= 3.3 kΩ.
The gain and phase bode diagrams are plotted respectively in Figure 11 and Figure 12.
Figure 11. Module plot
Figure 12. Phase plot
The cut-off frequency and the phase margin are:
Equation 16
F
C
30KHz=
Phase margin = 66.8°