參數(shù)資料
型號: AAT2500IWP-ET-T1
廠商: Advanced Analogic Technologies, Inc.
英文描述: 1MHz Step-Down Converter/LDO Regulator
中文描述: 1MHz的降壓轉(zhuǎn)換器/ LDO穩(wěn)壓器
文件頁數(shù): 17/26頁
文件大小: 881K
代理商: AAT2500IWP-ET-T1
In applications where the input power source lead
inductance cannot be reduced to a level that does
not affect the converter performance, a high ESR
tantalum or aluminum electrolytic should be placed
in parallel with the low ESR, ESL bypass ceramic.
This dampens the high Q network and stabilizes
the system.
Output Capacitor
The output capacitor limits the output ripple and
provides holdup during large load transitions. A
4.7μF to 10μF X5R or X7R ceramic capacitor typi-
cally provides sufficient bulk capacitance to stabi-
lize the output during large load transitions and has
the ESR and ESL characteristics necessary for low
output ripple.
The output voltage droop due to a load transient is
dominated by the capacitance of the ceramic out-
put capacitor. During a step increase in load cur-
rent, the ceramic output capacitor alone supplies
the load current until the loop responds. Within two
or three switching cycles, the loop responds and
the inductor current increases to match the load
current demand. The relationship of the output volt-
age droop during the three switching cycles to the
output capacitance can be estimated by:
Once the average inductor current increases to the
DC load level, the output voltage recovers. The
above equation establishes a limit on the minimum
value for the output capacitor with respect to load
transients.
The internal voltage loop compensation also limits
the minimum output capacitor value to 4.7μF. This
is due to its effect on the loop crossover frequency
(bandwidth), phase margin, and gain margin.
Increased output capacitance will reduce the
crossover frequency with greater phase margin.
The maximum output capacitor RMS ripple current
is given by:
Dissipation due to the RMS current in the ceramic
output capacitor ESR is typically minimal, resulting in
less than a few degrees rise in hot-spot temperature.
Adjustable Output Resistor Selection
For applications requiring an adjustable output volt-
age, the 0.6V version can be externally pro-
grammed. Resistors R1 and R2 of Figure 5 program
the output to regulate at a voltage higher than 0.6V.
To limit the bias current required for the external
feedback resistor string while maintaining good
noise immunity, the minimum suggested value for
1
2
3
V
OUT
· (V
IN(MAX)
- V
OUT
)
L
·
F
·
V
IN(MAX)
RMS(MAX)
I
=
·
·
C
OUT
=
3
·
Δ
I
LOAD
V
DROOP
·
F
S
AAT2500
1MHz Step-Down Converter/LDO Regulator
2500.2006.05.1.16
17
Figure 3: AAT2500 Evaluation Board Top Side.
Figure 4: AAT2500 Evaluation Board
Bottom Side.
相關(guān)PDF資料
PDF描述
AAT2500IWP-IP-T1 1MHz Step-Down Converter/LDO Regulator
AAT2500IWP-IW-T1 1MHz Step-Down Converter/LDO Regulator
AAT2504 Adjustable 3-Channel Regulator
AAT2504IZL-BAA-T1 Adjustable 3-Channel Regulator
AAT2505 Dual Channel, Step-Down Converter/Linear Regulator
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AAT2500IWP-IP-T1 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:1MHz Step-Down Converter/LDO Regulator
AAT2500IWP-IW-T1 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:1MHz Step-Down Converter/LDO Regulator
AAT2500M 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:400mA Step-Down Converter and 300mA LDO
AAT2500MITP-AW-T1 功能描述:開關(guān)變換器、穩(wěn)壓器與控制器 400mA Step-Down Convrt + 300mA LDO RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關(guān)頻率:1 MHz 工作溫度范圍: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel
AAT2503 制造商:ANALOGICTECH 制造商全稱:Advanced Analogic Technologies 功能描述:Adjustable 3-Channel Regulator