參數(shù)資料
型號: AAT1150
廠商: Advanced Analogic Technologies, Inc.
英文描述: GT 2C 2#4 SKT RECP
中文描述: 1MHz的第1A降壓型DC / DC轉(zhuǎn)換器
文件頁數(shù): 12/16頁
文件大小: 279K
代理商: AAT1150
AAT1150
1MHz 1A Step-Down DC/DC Converter
12
1150.2005.03.1.2
current varies with the input voltage and the output
voltage. The equation for the RMS current in the
input capacitor is:
The input capacitor RMS ripple current reaches a
maximum when V
IN
is two times the output voltage
where it is approximately one half of the load cur-
rent. Losses associated with the input ceramic
capacitor are typically minimal and are not an
issue. Proper placement of the input capacitor can
be seen in the reference design layout shown in
Figures 4 and 5.
Output Capacitor
Since there are no external compensation compo-
nents, the output capacitor has a strong effect on
loop stability. Larger output capacitance will reduce
the crossover frequency with greater phase margin.
For the 1.5V 1.0A design using the 4.1μH inductor,
two 22μF capacitors provide a stable output. In
addition to assisting stability, the output capacitor
limits the output ripple and provides holdup during
large load transitions.
The output capacitor RMS ripple current is given by:
For a ceramic capacitor, the dissipation due to the
RMS current of the capacitor is not a concern.
Tantalum capacitors, with sufficiently low ESR to
meet output voltage ripple requirements, also have
an RMS current rating much greater than that actu-
ally seen in this application.
Adjustable Output
For applications requiring an output other than the
fixed outputs available, the 1V version can be pro-
grammed externally (see Figure 6). Resistors R3
and R4 force the output to regulate higher than
1V. R4 should be 100 times less than the internal
1m
resistance of the FB pin. Once R4 is selected,
R3 can be calculated. For a 1.25V output with R4
set to 10k
, R3 is 2.55k
.
Layout Considerations
Figures 4 and 5 display the suggested PCB layout
for the AAT1150. The most critical aspect of the lay-
out is the placement of the input capacitor C1. For
proper operation, C1 must be placed as closely as
possible to the AAT1150.
Thermal Calculations
There are two types of losses associated with the
AAT1150 output switching MOSFET: switching
losses and conduction losses. Conduction losses
are associated with the R
DS(ON)
characteristics of
the output switching device. At full load, assuming
continuous conduction mode (CCM), a simplified
form of the total losses is:
Once the total losses have been determined, the
junction temperature can be derived from the
Θ
JA
for the MSOP-8 package.
I
2
(
R
V
+ R
(
V
- V
))
P
LOSS
=
V
IN
+ t
sw
F
I
O
V
IN
+ I
Q
V
IN
R3 = (V
O
- 1)
R4 = 0.25
10.0k
= 2.55k
V
OUT
(V
IN
- V
OUT
)
L
F
V
IN
1
I
RMS
=
2
3
V
O
V
O
V
IN
V
IN
I
RMS
= I
O
1 -
相關(guān)PDF資料
PDF描述
AAT1150IKS-1.0-T1 GT 2C 2#4 SKT RECP
AAT1150IKS-1.5-T1 GT 4C 4#4 PIN RECP
AAT1150IKS-1.8-T1 Circular Connector; MIL SPEC:MIL-C-5015; Body Material:Metal; Series:GT; No. of Contacts:4; Connector Shell Size:32; Connecting Termination:Solder; Circular Shell Style:Square Flange Receptacle; Body Style:Straight
AAT1150IKS-2.5-T1 1MHz 1A Step-Down DC/DC Converter
AAT1150IKS-3.3-T1 1MHz 1A Step-Down DC/DC Converter
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AAT1150_06 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:1MHz 1A Step-Down DC/DC Converter
AAT1150IKS-1.0-T1 制造商:Skyworks Solutions Inc 功能描述:SKYAAT1150IKS-1.0-T1 DC/DC CONVERTERS (S 制造商:SKYWORKS SOLUTIONS 功能描述:AAT1150 Series 5.5 V 1 MHz 1 A Synchronous Buck DC/DC Converter - MSOP-8 制造商:Skyworks Solutions Inc 功能描述:DC TO DC CONVERTER
AAT1150IKS-1.5-T1 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:1MHz 1A Step-Down DC/DC Converter
AAT1150IKS-1.8-T1 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:1MHz 1A Step-Down DC/DC Converter
AAT1150IKS-2.5-T1 制造商:SKYWORKS SOLUTIONS 功能描述:AAT1150 Series 5.5 V 1 MHz 1 A Synchronous Buck DC/DC Converter - MSOP-8