- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄375164 > AAT2500IWP-ET-T1 (Advanced Analogic Technologies, Inc.) 1MHz Step-Down Converter/LDO Regulator PDF資料下載
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)： | 16/26頁 |
| 文件大小： | 881K |
| 代理商： | AAT2500IWP-ET-T1 |
AAT2500
1MHz Step-Down Converter/LDO Regulator
16
2500.2006.05.1.16
Manufacturer's specifications list both the inductor
DC current rating, which is a thermal limitation, and
the peak current rating, which is determined by the
saturation characteristics. The inductor should not
show any appreciable saturation under normal load
conditions. Some inductors may meet the peak and
average current ratings yet result in excessive loss-
es due to a high DCR. Always consider the losses
associated with the DCR and its effect on the total
converter efficiency when selecting an inductor.
The 4.7μH CDRH3D16 series inductor selected
from Sumida has a 105m
Ω
DCR and a 900mA DC
current rating. At full load, the inductor DC loss is
17mW which gives a 2.8% loss in efficiency for a
400mA, 1.5V output.
Input Capacitor
Select a 4.7μF to 10μF X7R or X5R ceramic capac-
itor for the input. To estimate the required input
capacitor size, determine the acceptable input rip-
ple level (V
PP
) and solve for C. The calculated
value varies with input voltage and is a maximum
when V
IN
is double the output voltage.
Always examine the ceramic capacitor DC voltage
coefficient characteristics when selecting the prop-
er value. For example, the capacitance of a 10μF,
6.3V, X5R ceramic capacitor with 5.0V DC applied
is actually about 6μF.
The maximum input capacitor RMS current is:
The input capacitor RMS ripple current varies with
the input and output voltage and will always be less
than or equal to half of the total DC load current.
for V
IN
= 2 x V
OBUCK
The term
input voltage ripple and input capacitor RMS cur-
rent equations and is a maximum when V
OBUCK
is
twice V
IN
. This is why the input voltage ripple and
the input capacitor RMS current ripple are a maxi-
mum at 50% duty cycle.
appears in both the
The input capacitor provides a low impedance loop
for the edges of pulsed current drawn by the
AAT2500. Low ESR/ESL X7R and X5R ceramic
capacitors are ideal for this function. To minimize
stray inductance, the capacitor should be placed as
closely as possible to the IC. This keeps the high
frequency content of the input current localized,
minimizing EMI and input voltage ripple.
The proper placement of the input capacitor (C2)
can be seen in the evaluation board layout in
Figure 3.
A laboratory test set-up typically consists of two
long wires running from the bench power supply to
the evaluation board input voltage pins. The induc-
tance of these wires, along with the low-ESR
ceramic input capacitor, can create a high Q net-
work that may affect converter performance. This
problem often becomes apparent in the form of
excessive ringing in the output voltage during load
transients. Errors in the loop phase and gain meas-
urements can also result.
Since the inductance of a short PCB trace feeding
the input voltage is significantly lower than the
power leads from the bench power supply, most
applications do not exhibit this problem.
-
V
IN
V
OBUCK
V
OBUCK
V
IN
I
OBUCK
2
RMS(MAX)
I
=
· 1
-
= D
· (1 - D) = 0.5
2
=
V
IN
V
OBUCK
V
IN
1
2
I
RMS
= I
OBUCK
· · 1
-
OBUCK
V
IN
V
OBUCK
V
IN
C
IN(MIN)
=
1
- ESR
·
4
·
F
S
I
OBUCK
V
PP
-
= 1
IN
= 2
×
V
OBUCK
V
IN
V
IN
V
OBUCK
V
OBUCK
4
· 1
-
V
OBUCK
V
IN
I
OBUCK
C
IN
=
V
OBUCK
V
IN
- ESR
·
F
S
V
PP
相關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 |
相關代理商/技術參數(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 開關頻率:1 MHz 工作溫度范圍: 安裝風格: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 |
發(fā)布緊急采購，3分鐘左右您將得到回復。