- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄378285 > ADC14161 (National Semiconductor Corporation) Low Dropout Linear 2-cell Li-Ion Charge Controller with AutoCompTM, 8.4V 8-SOIC -20 to 70 PDF資料下載
參數(shù)資料
| 型號： | ADC14161 |
| 廠商： | National Semiconductor Corporation |
| 英文描述： | Low Dropout Linear 2-cell Li-Ion Charge Controller with AutoCompTM, 8.4V 8-SOIC -20 to 70 |
| 中文描述： | 低失真，自校準(zhǔn)14位，250 MSPS的，390毫瓦的A / D轉(zhuǎn)換器 |
| 文件頁數(shù)： | 17/20頁 |
| 文件大?。?/td> | 471K |
| 代理商： | ADC14161 |
Applications Information
(Continued)
5.0 LAYOUT AND GROUNDING
Proper grounding and proper routing of all signals are essen-
tial to ensure accurate conversion. Separate analog and
digital ground planes that are connected beneath the
ADC14161 are required to achieve specified performance.
The analog and digital grounds may be in the same layer, but
should be separated from each other and should never over-
lap each other. Separation should be at least
1
8
inch, where
possible.
The ground return for the digital supply (DGND I/O ) carries
the ground current for the output drivers. This output current
can exhibit high transients that could add noise to the con-
version process. To prevent this from happening, the DGND
I/O pin should
NOT
be connected in close proximity to any of
the ADC14161’s ground pins.
Capacitive coupling between the typically noisy digital
ground plane and the sensitive analog circuitry can lead to
poor performance that may seem impossible to isolate and
remedy. The solution is to keep the analog circuitry sepa-
rated from the digital circuitry and from the digital ground
plane.
Digital circuits create substantial supply and ground current
transients. The logic noise thus generated could have signifi-
cant impact upon system noise performance. The best logic
family to use in systems with A/D converters is one which
employs non-saturating transistor designs, or has low noise
characteristics, such as the 74LS, 74HC(T) and 74AC(T)Q
families. The worst noise generators are logic families that
draw the largest supply current transients during clock or sig-
nal edges, like the 74F and the 74AC(T) families.
Since digital switching transients are composed largely of
high frequency components, total ground plane copper
weight will have little effect upon the logic-generated noise.
This is because of the skin effect. Total surface area is more
important than is total ground plane volume.
An effective way to control ground noise is by connecting the
analog and digital ground planes together beneath the ADC
with a copper trace that is very narrow compared with the
rest of the ground plane. A typical width is 3/16 inch (4 to 5
mm).This narrowing beneath the converter provides a fairly
high impedance to the high frequency components of the
digital switching currents, directing them away from the ana-
log pins. The relatively lower frequency analog ground cur-
rents see a relatively low impedance across this narrow
ground connection.
Generally, analog and digital lines should cross each other at
90 degrees to avoid getting digital noise into the analog path.
To maximize accuracy in high speed, high resolution sys-
tems, however, avoid crossing analog and digital lines alto-
gether. It is important to keep any clock lines isolated from
ALL other lines, including other digital lines. Even the gener-
ally accepted 90 degree crossing should be avoided as even
a little coupling can cause problems at high frequencies.
This is because other lines can introduce phase noise (jitter)
into the clock line, which can lead to degradation of SNR.
Best performance at high frequencies and at high resolution
is obtained with a straight signal path. That is, the signal path
through all components should form a straight line wherever
possible.
Be especially careful with the layout of inductors. Mutual in-
ductance can change the characteristics of the circuit in
which they are used. Inductors should not be placed side by
side, even with just a small part of their bodies beside each
other.
The analog input should be isolated from noisy signal traces
to avoid coupling of spurious signals into the input. Any ex-
ternal component (e.g., a filter capacitor) connected be-
tween the converter’s input and ground should be connected
to a very clean point in the analog ground plane.
Figure 9gives an example of a suitable layout.All analog cir-
cuitry (input amplifiers, filters, reference components, etc.)
should be placed on or over the analog ground plane. All
digital circuitry and I/O lines should be placed over the digital
ground plane.
All ground connections should have a low inductance path to
ground.
A
www.national.com
17
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ADC14161CIVT | Low-Distortion, Self-Calibrating 14-Bit, 2.5 MSPS, 390 mW A/D Converter |
| ADC16061CCVT | Self-Calibrating 16-Bit, 2.5 MSPS, 390 mW A/D Converter |
| ADC16061 | Self-Calibrating 16-Bit, 2.5 MSPS, 390 mW A/D Converter(16位2.5 MSPS,390 mW可自行校對的A/D轉(zhuǎn)換器) |
| ADC16071 | 16-Bit Delta-Sigma 192 ks/s Analog-to-Digital Converters |
| ADC16471 | 16-Bit Delta-Sigma 192 ks/s Analog-to-Digital Converters |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ADC14161A EA | 制造商:Texas Instruments 功能描述: |
| ADC14161CIVT | 制造商:Rochester Electronics LLC 功能描述:- Tape and Reel |
| ADC14161EVAL | 功能描述:BOARD EVALUATION FOR ADC14161 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估板 - 模數(shù)轉(zhuǎn)換器 (ADC) 系列:- 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:- ADC 的數(shù)量:1 位數(shù):12 采樣率（每秒）:94.4k 數(shù)據(jù)接口:USB 輸入范圍:±VREF/2 在以下條件下的電源（標(biāo)準(zhǔn)）:- 工作溫度:-40°C ~ 85°C 已用 IC / 零件:MAX11645 已供物品:板，軟件 |
| ADC141S625CIMM | 功能描述:模數(shù)轉(zhuǎn)換器 - ADC RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32 |
| ADC141S625CIMM/NOPB | 功能描述:模數(shù)轉(zhuǎn)換器 - ADC RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。