AAT1164-Q5-T AAT [Advanced Analog Technology, Inc.], AAT1164-Q5-T Datasheet - Page 16

• Manufacturer Part Number: AAT1164-Q5-T
• Description: TRIPLE-CHANNEL TFT LCD POWER SOLUTION
• Manufacturer: AAT [Advanced Analog Technology, Inc.]

Example 1: In the typical application circuit (Figure 1)
the output load current is 300mA with 13.3V output
voltage and input voltage of 5V. Choose a k of 0.431
and efficiency of 90%.
P
Schottky Diode Selection
Schottky has to be able to dissipate power. The
dissipated power is the forward voltage and input DC
current. To achieve the best efficiency, choose a
Schottky diode with less recovery capacitor (C
recovery time and low forward voltage (V
For boost converter, the reverse voltage rating (V
should be higher than the maximum output voltage, and
current rating should exceed the input DC current.
P
P
Q
P
P
P
P
L
I
I
IN
L(peak )
DCR
DIODE
DSW
DCOM
DIODE
DSW
DCOM
R
≥
B220A
B240A
=
= V
SMA
0.431* 0.3 * 1.2
: Switching loss of diode for boost converter
= 0.0534W or 1.34% power loss
η(1 D)
= (1–D) V
: Conduction loss of diode for boost converter
: Total power loss of diode for boost converter
= V
= P
R
0.9 * 13.3
I
C
=
O
DIODES Product-Max Height: 2.3mm
−
T
I
F
DSW
IN
Q
I
O
R
+
= 0.886A
(1–D)
Table 2. Schottky Data List
+ P
V D
2Lf
F
IN
Q
0.24V
0.24V
DCOM
S
R
V
6
f
S
= 1.0778A
F
0.624(0.376)
Advanced Analog Technology, Inc.
14V
28V
V
2
R
≈ 6.8 H
µ
F
).
–
150pF
150pF
–
Advanced Analog Technology, Inc . –
T
C
) for fast
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T
Page 16 of 24
Version 1.00
R
)
For example,
P
Input Capacitor Selection
The input capacitors have two important functions in
PWM controller. First, an input capacitor provides the
power for soft start procedure and supply the current for
the gate-driving circuit. A 10 F
used in typical circuit. Second, an input bypass
capacitor reduces the current peaks, the input voltage
drop, and noise injection into the IC. A low ESR
ceramics capacitor 0.1 F
ensure the low noise supply at V
from input capacitor using an RC low pass filter.
Figure 3. Input Bypass Capacitor Affects the V
Output Capacitor
The output capacitor maintains the DC output voltage. A
Low ESR (
ripple and power loss. There are two parameters which
can affect the output voltage ripple: 1. the voltage drops
when the inductor current flows through the ESR of
output capacitor; 2. charging and discharging of the
output capacitor also affect the output voltage ripple.
V
AAT1164/AAT1164B/AAT1164C
DIODE
RIPPLE
= P
VDD
VDD
=
–
DSW
Drop.
r
V
C
RIPPLE
) ceramic capacitor can reduce the output
+ P
DCOM
(C
OUT
= 0.0273W or 0.68% power loss.
µ
) V
+
is used in typical circuit. To
RIPPLE
µ
DD
ceramic capacitor is
, V
(ESR)
DD
is decoupled
April 2007
DD