Datasheet

LTC3538
13
3538fb
V
OUT
R1
1V
FB
C
P2
C
P1
RZ
V
C
R2
C
Z1
3538 F05
–
+
1
2
Figure 5. Error Amplifi er with Type III Compensation
OPERATION
Most applications demand an improved transient response
to allow a smaller output fi lter capacitor. To achieve a higher
bandwidth, Type III compensation is required, providing
two zeros to compensate for the double-pole response of
the output fi lter. Referring to Figure 5, the location of the
poles and zeros are given by:
ƒ
POLE1
≅
1
2• π • 32e
3
•R1•C
P1
Hz
(which is extremly close to DC)
ƒ
ZERO1
=
1
2• π •R
Z
•C
P1
Hz
ƒ
ZERO2
=
1
2• π •R1•C
Z1
Hz
ƒ
POLE2
=
1
2• π •R
Z
•C
P2
Hz
where resistance is in Ohms and capacitance is in
Farads.