- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄1982 > AD7709ARU (Analog Devices Inc)IC ADC 16BIT SIGMA-DELTA 24TSSOP PDF資料下載
參數(shù)資料
| 型號： | AD7709ARU |
| 廠商： | Analog Devices Inc |
| 文件頁數(shù)： | 18/32頁 |
| 文件大?。?/td> | 0K |
| 描述： | IC ADC 16BIT SIGMA-DELTA 24TSSOP |
| 產(chǎn)品變化通告： | Product Discontinuance 27/Oct/2011 |
| 標(biāo)準包裝： | 62 |
| 位數(shù)： | 16 |
| 采樣率（每秒）： | 105 |
| 數(shù)據(jù)接口： | DSP，MICROWIRE?，QSPI?，串行，SPI? |
| 轉(zhuǎn)換器數(shù)目： | 1 |
| 功率耗散（最大）： | 3.75mW |
| 電壓電源： | 單電源 |
| 工作溫度： | -40°C ~ 85°C |
| 安裝類型： | 表面貼裝 |
| 封裝/外殼： | 24-TSSOP（0.173"，4.40mm 寬） |
| 供應(yīng)商設(shè)備封裝： | 24-TSSOP |
| 包裝： | 管件 |
| 輸入數(shù)目和類型： | 2 個差分，單極；2 個差分，雙極；4 個偽差分，單極；4 個偽差分，雙極 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁當(dāng)前第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁
REV. A
AD7709
–25–
The printed circuit board that houses the AD7709 should be
designed such that the analog and digital sections are separated
and confined to certain areas of the board. A minimum etch
technique is generally best for ground planes as it gives the best
shielding.
It is recommended that the AD7709 GND pin be tied to the
AGND plane of the system. In any layout, it is important that the
user keep in mind the flow of currents in the system ensuring
that the return paths for all currents are as close as possible to
the paths the currents took to reach their destinations. Avoid
forcing digital currents to flow through the AGND sections of
the layout.
The PWRGND pin is tied internally to GND on the AD7709.
The PWRGND pad internally has a resistance of less than 50 m
W
to the PWRGND pin, while the resistance back to the GND pad
is less than 3
W. This means that 19.5 mA of the maximum speci-
fied current (20 mA) will flow to PWRGND with the remaining
0.5 mA flowing to GND. PWRGND and GND should be tied
together at the AD7709, and it is important to minimize the
resistance on the ground return lines.
Avoid running digital lines under the device since these will
couple noise onto the die. The analog ground plane should be
allowed to run under the AD7709 to prevent noise coupling.
The power supply lines to the AD7709 should use as wide a trace as
possible to provide low impedance paths and reduce the effects of
glitches on the power supply line. Fast switching signals like
clocks should be shielded with digital ground to avoid radiating
noise to other sections of the board, and clock signals should
never be run near the analog inputs. Avoid crossover of digital
and analog signals. Traces on opposite sides of the board should
run at right angles to each other, which will reduce the effects of
feedthrough through the board. A microstrip technique is by far the
best, but is not always possible with a double-sided board. In
this technique, the component side of the board is dedicated to
ground planes while signals are placed on the solder side.
Good decoupling is important when using high resolution ADCs.
The supply should be decoupled with 10
mF tantalum in parallel
with 0.1
mF capacitors to GND. To achieve the best from these
decoupling components, they have to be placed as close as possible;
chips should be decoupled with 0.1
mF ceramic capacitors to DGND.
APPLICATIONS
The AD7709 provides a low cost, high resolution, analog-to-digital
function. Because the analog-to-digital function is provided by a
-
architecture, it makes the part more immune to noisy
environments, making it ideal for use in sensor measurement and
industrial and process control applications. Given the architecture
used in the AD7709, where the signal chain is chopped and the
device is factory-calibrated at final test, field calibration is not
needed due to the extremely low offset and gain drifts exhibited
by this converter. It also provides a programmable gain amplifier
and a digital filter. Thus, it provides far more system-level func-
tionality than off-the-shelf integrating ADCs without the
disadvantage of having to supply a high quality integrating
capacitor. In addition, using the AD7709 in a system allows the
system designer to achieve a much higher level of resolution because
noise performance of the AD7709 is significantly better than that
of integrating ADCs.
The on-chip PGA allows the AD7709 to handle an analog input
voltage range as low as 10 mV full scale with VREF = 1.25 V. The
differential inputs of the part allow this analog input range to
have an absolute value anywhere between GND + 100 mV and
VDD – 100 mV. It allows the user to connect the transducer
directly to the input of the AD7709. The programmable gain
front end on the AD7709 allows the part to handle unipolar
analog input ranges from 0 mV to 20 mV and 0 V to 2.5 V
and bipolar inputs of
±20 mV to ±2.5 V. Because the part oper-
ates from a single supply, these bipolar ranges are with respect
to a biased-up differential input.
Pressure Measurement
One typical application of the AD7709 is pressure measurement.
Figure 18 shows the AD7709 used with a pressure transducer,
the BP01 from Sensym. The pressure transducer is arranged in
a bridge network and gives a differential output voltage between
its OUT(+) and OUT(–) terminals. With rated full-scale pres-
sure (in this case 300 mmHg) on the transducer, the differential
output voltage is 3 mV/V of the input voltage (i.e., the voltage
between its IN(+) and IN(–) terminals).
Assuming a 5 V excitation voltage, the full-scale output range
from the transducer is 15 mV. The excitation voltage for the
bridge can be used to directly provide the reference for the ADC
as the reference input range includes the supply. Alternatively, a
suitable resistor divider can be implemented that allows the full
dynamic range of the input to be utilized in this application.
This implementation is fully ratiometric, so variations in the
excitation voltage do not introduce errors in the system. Choosing
resistor values of 10 k
W and 6 kW as per Figure 18 gives a 1.875 V
reference voltage for the AD7709 when the excitation voltage is 5 V.
AD7709
IN+
OUT+
OUT–
IN–
10k
EXCITATION VOLTAGE = 5V
VDD
AIN1
AIN2
REFIN1(+)
P1
PWRGND
GND
REFIN2(–)
6k
Figure 18. Pressure Measurement Using the AD7709
Using the part with a programmed gain of 128 results in the
full-scale input span of the AD7709 being 15 mV, which corre-
sponds with the output span from the transducer.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| AD7710AQ | IC ADC 24BIT DIFF INP 24-CDIP |
| AD7711AAR | IC ADC 24BIT RTD I SOURCE 24SOIC |
| AD7711AN | IC ADC 24BIT RTD I SOURCE 24-DIP |
| AD7712AR | IC ADC SIGNAL COND LC2MOS 24SOIC |
| AD7713AN | IC ADC 24BIT SIGMA-DELTA 24-DIP |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AD7709ARU-REEL | 功能描述:IC ADC 16BIT SIGMA-DELTA 24TSSOP RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標(biāo)準包裝:1,000 系列:- 位數(shù):16 采樣率（每秒）:45k 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:2 功率耗散（最大）:315mW 電壓電源:模擬和數(shù)字 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:28-SOIC（0.295"，7.50mm 寬） 供應(yīng)商設(shè)備封裝:28-SOIC W 包裝:帶卷 (TR) 輸入數(shù)目和類型:2 個單端，單極 |
| AD7709ARU-REEL7 | 制造商:Analog Devices 功能描述:ADC Single Delta-Sigma 105sps 16-bit Serial 24-Pin TSSOP T/R 制造商:Analog Devices 功能描述:ADC SGL DELTA-SIGMA 0.105KSPS 16BIT SERL 24TSSOP - Tape and Reel |
| AD7709ARUZ | 功能描述:IC ADC 16BIT SIGMA-DELTA 24TSSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 其它有關(guān)文件:TSA1204 View All Specifications 標(biāo)準包裝:1 系列:- 位數(shù):12 采樣率（每秒）:20M 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:2 功率耗散（最大）:155mW 電壓電源:模擬和數(shù)字 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:48-TQFP 供應(yīng)商設(shè)備封裝:48-TQFP（7x7） 包裝:Digi-Reel® 輸入數(shù)目和類型:4 個單端，單極；2 個差分，單極 產(chǎn)品目錄頁面:1156 (CN2011-ZH PDF) 其它名稱:497-5435-6 |
| AD7709ARUZ-REEL7 | 功能描述:IC ADC 16BIT SIGMA-DELTA 24TSSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標(biāo)準包裝:1,000 系列:- 位數(shù):16 采樣率（每秒）:45k 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:2 功率耗散（最大）:315mW 電壓電源:模擬和數(shù)字 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:28-SOIC（0.295"，7.50mm 寬） 供應(yīng)商設(shè)備封裝:28-SOIC W 包裝:帶卷 (TR) 輸入數(shù)目和類型:2 個單端，單極 |
| AD7709BR | 制造商:AD 制造商全稱:Analog Devices 功能描述:16-Bit Sigma Delta ADC with Current Sources, Switchable Reference Inputs and I/O Port |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。