AAT1168-Q5-T AAT [Advanced Analog Technology, Inc.], AAT1168-Q5-T Datasheet - Page 18

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

5. The output filter capacitor is chosen so C
cancels
Example 3:
Figure 7. Bode Plot of Loop Gain Using Matlab
Simulation
R
C
r = 76.689 m
r
V = 5V,
V
L
C
R C
C
IN
FB
C
= 9.13m
C C
21.533µF
25.079µF
32.587µF
36.312µF
38.469µF
= 7.6k
1 (
= 1.233V, L = 6.65µH,
~
-135
-180
-225
-270
R
C
-20
-40
-90
C
60
40
20
0
) 3
C
R
C



C



V = 13.3V,
R
R
2
O
, C = 38.5µF,
L
C
2
L
,
C
10
2
R = 0.7667
Table 3 K factor Table
r
C
r
zero
F
C






, and
Best Corner
23.740 kHz
21.842 kHz
20.095 kHz
15.649 kHz
13.247 kHz
Frequency
10
3
I = 300mA,
O
Frequency (Hz)
Advanced Analog Technology, Inc
Bode Diagram
G = 85µS,
= 3,
,
m
10
4
C
C
R
= 1.95nF,
CS
f = 1,190kHz,
s
10
= 0.23V/A.
5
–
K factor
4.692
5.083
6.042
5.230
4.703
Advanced Analog Technology, Inc . –
–
R
台 灣 類 比 科 技 股 份 有 限 公 司
10
L
6
pole
®
Page 18 of 22
Version 1.00
Positive and Negative LDO driver
Output Voltage Selection
The output voltage of positive LDO driver is set by a
resistive divider from the output (Vout3) to GND with
the center tap connected to the IN3, where V
positive LDO driver feedback regulation voltage, is
1.25V. Choose R
51k
The output voltage of negative LDO driver is set by a
resistive divider from the output (VGL) to VREF with
the center tap connected to the IN2, where V
negative LDO driver feedback regulation voltage, is
0.25V. Choose R
51k
R
R
5
8
R
R
. And calculate R
and calculate R
6
9





 

–
Figure 8. The Positive LDO Driver
V
Vout
V
V
REF
IN
IN
2
3
3
AAT1168/1168A/1168B
V
.
V
1
GL
IN
9
6




2
(Figure 8) between 10k
(Figure 9) between 10k
8

 

5
with the following equation.
with the following equation.
May 2008
IN3
IN2,
, the
and
and
the