L6725_07 STMICROELECTRONICS [STMicroelectronics], L6725_07 Datasheet - Page 21

• Manufacturer Part Number: L6725_07
• Description: Voltage mode PWM controller with bootstrap anti-discharging system
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

L6725 - L6725A
Figure 15. Asymptotic Bode plot of Converter's open loop gain
●
●
●
Modulator singularity frequencies:
Compensation network singularity frequencies:
Compensation network design:
–
–
–
–
–
–
Put the gain R
Place
Place
Place
Place
Check the loop gain considering the error amplifier open loop gain.
ω
ω
P
Z
1
1
ω
=
ω
ω
ω
ω
=
LC
Z1
Z2
P1
P2
R
R
5
=
5
before the output filter resonance
at the output filter resonance
at the output capacitor ESR zero
at one half of the switching frequency;
⋅
1
⋅
⎛
⎜ ⎜
⎝
C
C
5
19
C
L
/R
18
1
18
⋅
1
ϖ
Cout
3
+
⋅
in order to obtain the desired converter bandwidth:
C
C
C
(12)
19
=
19
⎞
⎟ ⎟
⎠
R
R
5
3
(8)
(10)
⋅
∆
Vin
Vosc
ω
⋅
ϖ
ω
Z
2
LC
ESR
ω
ω
=
LC
P
=
C
(14)
2
;
ω
ω
20
ESR
=
ESR
LC
⋅
R
(
R
;
4
1
;
1
⋅
3
⋅
1
Cout
C
+
20
R
4
)
(11)
(9)
(13)
Application details
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