AAT1168-Q5-T AAT [Advanced Analog Technology, Inc.], AAT1168-Q5-T Datasheet - Page 17

• Manufacturer Part Number: AAT1168-Q5-T
• Description: TRIPLE-CHANNEL TFT LCD POWER SOLUTION WITH OPERATIONAL AMPLIFIERS
• Manufacturer: AAT [Advanced Analog Technology, Inc.]

Current Sampling Transfer Function
Error voltage to duty transfer function
Where
Therefore,
transfer function
frequency;
transresistance.
For the boost converter,
(
For AAT1168,
compensation,
The closed-current loop transfer function
The Voltage-Loop Gain with Current Loop
Closed
The control to output voltage transfer function
The voltage-loop gain with current loop closed is:
F (s)
L (s) = T (s)T (s)
T (s) =
T (s) =
w
m
V −
s
icl
d
vi
s
O
g R
m C
w
2 f
s
V )/ L .
zi
w
IN
v
V (s)
V (s)
d
R
s (
ei
sh
s
O
C
w
s
12f
CS pi0
C
2
1 z
F
s
R
T
s
T R
w
m
3
2
sw
pi0 CS
CS
= T (s)T (s)
s
c
2f
w
R
d
M = 0.8×10
depends on duty to inductor current
s
12f T
CS
R
s
s
x
icl
2
T , and
w
a
h
CS pi0



(
pi
is
s + w
s
s
z
1
1
= 0.24 V/A,
s s w
2
2
2
T
12
(
p0
p
the
2 w s w
s + 2 w s + w
f
s
zi



2
M =
2
Advanced Analog Technology, Inc
,
)
)
1
zi
(
n
s + w s +12f
6.
f is the clock switching
2
s
current-sense
V / L and
s w
IN
M
M
n
M
n
2
1
2
a
sh
sh
M
M
is slope
a
F
a
n
2
m
)
–
T
icl
M =
is:
s
2
2
is :
)
Advanced Analog Technology, Inc . –
–
amplifier
T is :
台 灣 類 比 科 技 股 份 有 限 公 司
d
Page 17 of 22
Version 1.00
Where
The compensator transfer function
Where
Compensator design guide:
1. Crossover frequency
2. Gain margin>10dB
3. Phase margin>45
4. The
the compensator resistance,
R
T (s)
w
C
C
c
R C
V
V
FB
C C
O
v
V
1
Figure 6. Voltage Loop Compensator
L
fb
=
C
–
vi
2 f CR
V
(
V
) s
FB
O
ci
g R
g k
m C
m
1
AAT1168/1168A/1168B
CS
.
s w
at crossover frequency, Therefore,
∘




s
1 D R
c
f
ci
R
L
2
L
1
R
2r
f
s
C
C
1 D
r
is determined by:




May 2008