AAT1164C Advanced Analog Technology, AAT1164C Datasheet - Page 15

• Manufacturer Part Number: AAT1164C
• Description: TRIPLE-CHANNEL TFT LCD POWER SOLUTION
• Manufacturer: Advanced Analog Technology

DESIGN PROCEDURE
Boost Converter Design
Setting the Output Voltage and Selecting
the Lead Compensation Capacitor
The output voltage of boost converter is set by the
resistor divider from the output (V
center tap connected to IN1, where V
converter feedback regulation voltage is 1.233V,
Choose R
calculate R
Inductor Selection
The minimum inductance value is selected to make
sure that the system operates in continuous conduction
mode (CCM) for high efficiency and to prevent EMI. The
equation of inductor uses a parameter k, which is the
ratio of the inductor peak to peak ripple current to the
input DC current. The best trade-off between voltage
ripple of transient output current and permanent output
current has a k between 0.4 and 0.5.
R
L
D 1
≥
1
= −
=
kI f
ηV
O S
R
O
V
V
2
IN
O ,



D(1 D)
V
V
2
OUT1
1
−
IN1
to satisfy the following equation.
(Figure 2) between 5.1k
Figure 2. Feedback Circuit
2
−
,
1



Advanced Analog Technology, Inc.
OUT1
) to GND with the
IN1
–
to 51k
, the boost
–
Advanced Analog Technology, Inc . –
台 灣 類 比 科 技 股 份 有 限 公 司
and
Page 15 of 24
Version 1.00
∆I
k =
η
k: The ratio of the inductor peak to peak ripple current to
V
V
I
f
D: Duty cycle
I
The AAT1164 SW current limit (
saturation current rating (
and the inductor's DC current rating should exceed I
For the best efficiency, choose an inductor with less DC
series resistance (
I
P
I
I
I
I
P
O
IN
LDC
S
L(peak)
IN
LIM
LDC
AAT1164/AAT1164B/AAT1164C
DCR
: Boost converter efficiency
IN
O
DCR
: Switching frequency
: Output load current
Lpeak–peak
: Input DC current
: Output voltage
C6-K1.8L
: Input voltage
=
the input DC current
: DC current rating of inductor
∆I
3.9 µ H
6.8 µ H
10 µ H
: Power loss of inductor series resistance
>
η(1 D)
and
Lpeak-peak
≈ 
I
IN
MITSUMI Product-Max Height:1.9mm
=


I
O
I
−
IN
η(1 D)
I
–
IN
: Inductor peak to peak ripple current
I
LSAT
I
O
+
−
V D
2Lf
,
Table 1. Inductor Data List
IN



S
>
2
68m
r
81m
41m
,
r ).
L
I
L
L(peak )
r
L
I
LSAT
DC CURRENT RATING
) should exceed I
I
LIM
2.5A
2.2A
1.8A
) and inductor’s
April 2007
L(peak)
IN
,
.