參數(shù)資料
型號: AD7789BRM
廠商: ANALOG DEVICES INC
元件分類: ADC
英文描述: Low Power, 16-/24-Bit Sigma-Delta ADC
中文描述: 1-CH 24-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PDSO10
封裝: MO-187BA, MSOP-10
文件頁數(shù): 18/20頁
文件大?。?/td> 288K
代理商: AD7789BRM
AD7788/AD7789
Reference voltage sources like those recommended above (e.g.,
ADR391) will typically have low output impedances and are,
therefore, tolerant to having decoupling capacitors on REFIN(+)
without introducing gain errors in the system. Deriving the
reference input voltage across an external resistor will mean that
the reference input sees a significant external source impedance.
External decoupling on the REFIN pins would not be
recommended in this type of circuit configuration.
Rev. 0 | Page 18 of 20
V
DD
MONITOR
Along with converting external voltages, the analog input chan-
nel can be used to monitor the voltage on the V
DD
pin. When the
CH1 and CH0 bits in the communications register are set to 1,
the voltage on the V
DD
pin is internally attenuated by 5 and the
resultant voltage is applied to the ∑- modulator using an inter-
nal 1.17 V reference for analog to digital conversion. This is
useful because variations in the power supply voltage can be
monitored.
GROUNDING AND LAYOUT
Since the analog inputs and reference inputs of the ADC are
differential, most of the voltages in the analog modulator are
common-mode voltages. The excellent common-mode
rejection of the part will remove common-mode noise on these
inputs. The digital filter will provide rejection of broadband
noise on the power supply, except at integer multiples of the
modulator sampling frequency. The digital filter also removes
noise from the analog and reference inputs, provided that these
noise sources do not saturate the analog modulator. As a result,
the AD7788/AD7789 is more immune to noise interference
than a conventional high resolution converter. However,
because the resolution of the AD7788/AD7789 is so high, and
the noise levels from the AD7788/AD7789 are so low, care must
be taken with regard to grounding and layout.
The printed circuit board that houses the AD7788/AD7789
should be designed such that the analog and digital sections are
separated and confined to certain areas of the board. A mini-
mum etch technique is generally best for ground planes because
it gives the best shielding.
It is recommended that the AD7788/AD7789’s 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 destina-
tions. Avoid forcing digital currents to flow through the AGND
sections of the layout.
The AD7788/AD7789’s ground plane should be allowed to run
under the AD7788/AD7789 to prevent noise coupling. The
power supply lines to the AD7788/AD7789 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 sig-
nals such as 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 cross-
over of digital and analog signals. Traces on opposite sides of
the board should run at right angles to each other. This will
reduce the effects of feedthrough through the board. A micro-
strip technique is by far the best, but it 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. V
DD
should be decoupled with 10 μF tantalum in parallel
with 0.1 μF capacitors to GND. To achieve the best from these
decoupling components, they should be placed as close as
possible to the device, ideally right up against the device. All
logic chips should be decoupled with 0.1 μF ceramic capacitors
to DGND.
相關(guān)PDF資料
PDF描述
AD7788BRM Low Power, 16-/24-Bit Sigma-Delta ADC
AD7788BRM-REEL Low Power, 16-/24-Bit Sigma-Delta ADC
AD7789BRM-REEL Low Power, 16-/24-Bit Sigma-Delta ADC
AD7790 Low Power, 16-Bit Buffered Sigma-Delta ADC
AD7790B Low Power, 16-Bit Buffered Sigma-Delta ADC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7789BRM-REEL 功能描述:IC ADC 24BIT SIGMA-DELTA 10-MSOP 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(zhǔn)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
AD7789BRMZ 功能描述:IC ADC 24BIT LP 10-MSOP 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(zhǔn)包裝:1 系列:microPOWER™ 位數(shù):8 采樣率(每秒):1M 數(shù)據(jù)接口:串行,SPI? 轉(zhuǎn)換器數(shù)目:1 功率耗散(最大):- 電壓電源:模擬和數(shù)字 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:24-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:24-VQFN 裸露焊盤(4x4) 包裝:Digi-Reel® 輸入數(shù)目和類型:8 個單端,單極 產(chǎn)品目錄頁面:892 (CN2011-ZH PDF) 其它名稱:296-25851-6
AD7789BRMZ-REEL 功能描述:IC ADC 24BIT SIGMA-DELTA 10MSOP 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(zhǔn)包裝:2,500 系列:- 位數(shù):16 采樣率(每秒):15 數(shù)據(jù)接口:MICROWIRE?,串行,SPI? 轉(zhuǎn)換器數(shù)目:1 功率耗散(最大):480µW 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:38-WFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:38-QFN(5x7) 包裝:帶卷 (TR) 輸入數(shù)目和類型:16 個單端,雙極;8 個差分,雙極 配用:DC1011A-C-ND - BOARD DELTA SIGMA ADC LTC2494
AD779 制造商:AD 制造商全稱:Analog Devices 功能描述:14-Bit 128 kSPS Complete Sampling ADC
AD7790 制造商:AD 制造商全稱:Analog Devices 功能描述:Low Power, 16-Bit Buffered Sigma-Delta ADC