參數(shù)資料
型號： AD7946BCPRL7
廠商： ANALOG DEVICES INC
元件分類： ADC
英文描述： 14-Bit, 500 kSPS PulSAR⑩ ADC in MSOP/QFN
中文描述： 1-CH 14-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO10
封裝： 3 X 3 MM, QFN-10
文件頁數(shù)： 6/27頁
文件大?。?/td> 301K
代理商： AD7946BCPRL7
AD7946
Preliminary Technical Data
Rev Pr D | Page 14 of 27
Analog Input
Figure 23 shows an equivalent circuit of the input structure of
the AD7946.
The two diodes, D1 and D2, provide ESD protection for the
analog inputs IN+ and IN. Care must be taken to ensure that
the analog input signal never exceeds the supply rails by more
than 0.3 V because this will cause these diodes to become
forward-biased and start conducting current. However, these
diodes can handle a forward-biased current of 130 mA
maximum. For instance, these conditions could eventually
occur when the input buffer’s (U1) supplies are different from
VDD. In such a case, an input buffer with a short-circuit
current limitation can be used to protect the part.
CIN
RIN
D1
D2
CPIN
IN+
OR IN–
GND
VDD
Figure 23. Equivalent Analog Input Circuit
This analog input structure allows the sampling of the
differential signal between IN+ and IN. By using this
differential input, small signals common to both inputs are
rejected, as shown in Figure 24, which represents the typical
CMRR over frequency. For instance, by using IN to sense a
remote signal ground, ground potential differences between the
sensor and the local ADC ground are eliminated.
Figure 24. Analog Input CMRR vs. Frequency
During the acquisition phase, the impedance of the analog
input IN+ can be modeled as a parallel combination of
capacitor C1 and the network formed by the series connection
of R1 and C2. C1 is primarily the pin capacitance. R1 is typically
600 and is a lumped component made up of some serial
resistors and the on resistance of the switches. C2 is typically
30 pF and is mainly the ADC sampling capacitor. During the
conversion phase, where the switches are opened, the input
impedance is limited to C1. R1 and C2 make a 1-pole, low-pass
filter that reduces undesirable aliasing effect and limits the
noise.
When the source impedance of the driving circuit is low, the
AD7946 can be driven directly. Large source impedances
significantly affect the ac performance, especially total
harmonic distortion (THD). The dc performances are less
sensitive to the input impedance. The maximum source
impedance depends on the amount of THD that can be
tolerated. The THD degrades as a function of the source
impedance and the maximum input frequency, as shown in
Figure 25.
Figure 25. THD vs. Analog Input Frequency and Source Resistance
相關(guān)PDF資料
PDF描述
AD574AK Complete 12-Bit A/D Converter
AD574AL Complete 12-Bit A/D Converter
AD574ALD Complete 12-Bit A/D Converter
AD574ALN Complete 12-Bit A/D Converter
AD574ASD Complete 12-Bit A/D Converter
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7946BCPWP 制造商:AD 制造商全稱:Analog Devices 功能描述:14-Bit, 500 kSPS PulSAR⑩ ADC in MSOP/QFN
AD7946BCPZRL 功能描述:IC ADC 14BIT 500KSPS 10-LFCSP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:PulSAR® 標準包裝:1,000 系列:- 位數(shù):12 采樣率（每秒）:300k 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:1 功率耗散（最大）:75mW 電壓電源:單電源 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:24-SOIC（0.295"，7.50mm 寬） 供應商設(shè)備封裝:24-SOIC 包裝:帶卷 (TR) 輸入數(shù)目和類型:1 個單端，單極；1 個單端，雙極
AD7946BCPZRL7 功能描述:IC ADC 14BIT 500KSPS 10-LFCSP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:PulSAR® 標準包裝:1,000 系列:- 位數(shù):12 采樣率（每秒）:300k 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:1 功率耗散（最大）:75mW 電壓電源:單電源 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:24-SOIC（0.295"，7.50mm 寬） 供應商設(shè)備封裝:24-SOIC 包裝:帶卷 (TR) 輸入數(shù)目和類型:1 個單端，單極；1 個單端，雙極
AD7946BRM 制造商:Analog Devices 功能描述: 制造商:Rochester Electronics LLC 功能描述:
AD7946BRMRL7 制造商:AD 制造商全稱:Analog Devices 功能描述:14-Bit, 500 kSPS PulSAR⑩ ADC in MSOP/QFN
發(fā)布緊急采購，3分鐘左右您將得到回復。

采購需求

(若只采購一條型號，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

*型號 *數(shù)量 廠商 批號 封裝
添加更多采購

我的聯(lián)系方式

*
*
*