AAT1102 Advanced Analog Technology, Inc., AAT1102 Datasheet - Page 10

• Manufacturer Part Number: AAT1102
• Description: ADVANCED PWM DC-DC CONVERTER WITH INTERNAL SWITCH AND SOFT-START
• Manufacturer: Advanced Analog Technology, Inc.

Inductor selection
And
The inductor current rating must be greater than
Loop Compensation Design
Fig.1. Closed-current loop for boost with PCM
Fig.2. Block diagram of boost converter with
I
I
L
L(peak)
(
peak
I
IN
)
PCM
.
=
=
I
IN
1
−
I
+
o
D
V
2
IN
Lf
,
D
s
D
Advanced Analog Technology, Inc.
, where D is duty cycle
= 1
−
–
V
V
–
IN
o
Advanced Analog Technology, Inc
,
台灣類比科技股份有限公司
Page 10 of 18
Power Stage Transfer Functions
The duty to output voltage transfer function
Where
And
is capacitor ESR,
resistance, C is output filter capacitor,
transistor on-resistance, and
forward resistance.
The duty to inductor current transfer function
Where
T
ξ
T
w
r
r
L
p
pi
z
=
=
(
2
(
s
is the inductor equivalent series resistance,
r
s
C
=
)
2
L
)
[
=
+
=
T
R
r
LC
T
(
p
L
v
Dr
d
i
d
R
0
pi
(
l
o
1
L
0
=
(
=
DS
=
−
R
+
=
V
L
T
T
D
L
+
O
r
V
pi
p
c
+
)
0
O
1 ( −
0
L
(
)
2
1
(
+
r
(
(
s
s
−
R
−
c
R
s
R is the converter load
2
2
R
)
L
L
r
[
+
D
D
+
L
r
+
L
+
+
,
w
−
r
)
)(
+
2
2
w
c
s
R
2
r
esr
ξ
R
ξ
r
(
c
–
(
n
1
+
r
F
c
1
w
)
w
c
L
AAT1102 (BIN2)
)(
−
=
)
−
w
n
.
n
+
,
s
s
–
s
D
zi
D
w
r
+
−
+
c
R
)
(
)
zi
1
2
)
w
2
w
w
LC
F
]
−
=
,
R
n
z
n
+
w
2
2
L
2
D
is the diode
C
(
)
esr
L
]
R
)
(
2
R
L
,
=
R
L
+
L
Cr
2 /
1
r
1
+
c
r
c
)
DS
+
r
r
T
c
is the
)
p
T
V5.0
r
pi
c
is :
is: