2 × VREF p-p GND 440 " />
參數(shù)資料
型號(hào)： AD7938BCPZ
廠(chǎng)商： Analog Devices Inc
文件頁(yè)數(shù)： 15/36頁(yè)
文件大?。?/td> 0K
描述： IC ADC 12BIT 8CH 1.5MSPS 32LFCSP
標(biāo)準(zhǔn)包裝： 1
位數(shù)： 12
采樣率（每秒）： 1.5M
數(shù)據(jù)接口： 并聯(lián)
轉(zhuǎn)換器數(shù)目： 1
功率耗散（最大）： 13.5mW
電壓電源： 單電源
工作溫度： -40°C ~ 85°C
安裝類(lèi)型： 表面貼裝
封裝/外殼： 32-VFQFN 裸露焊盤(pán)，CSP
供應(yīng)商設(shè)備封裝： 32-LFCSP-VQ
包裝： 托盤(pán)
輸入數(shù)目和類(lèi)型： 8 個(gè)單端，單極；4 個(gè)差分，單極；4 個(gè)偽差分，單極；7 偽差分，單極
配用： EVAL-AD7938CBZ-ND - EVAL BOARD FOR AD7938
AD7938/AD7939
Data Sheet
Rev. C | Page 22 of 36
220
10k
2 × VREF p-p
GND
440
220
220
20k
220
27
27
V+
V–
V+
V–
A
VIN+
VIN–
VREF
AD7938/
AD7939
0.47F
03715-
035
3.75V
2.5V
1.25V
3.75V
2.5V
1.25V
+
Figure 28. Dual Op Amp Circuit to Convert a Single-Ended
Bipolar Signal into a Differential Unipolar Signal
10k
VREF p-p
VREF
GND
440
220
220
20k
220
27
27
V+
V–
V+
V–
A
VIN+
VIN–
VREF
AD7938/
AD7939
0.47F
03715-
036
3.75V
2.5V
1.25V
3.75V
2.5V
1.25V
+
Figure 29. Dual Op Amp Circuit to Convert a Single-Ended Unipolar Signal
into a Differential Signal
Another method of driving the AD7938/AD7939 is to use the
AD8138 differential amplifier. The AD8138 can be used as a
single-ended-to-differential amplifier or as a differential-to-
differential amplifier. The device is as easy to use as an op amp
and greatly simplifies differential signal amplification and
driving.
Pseudo Differential Mode
The AD7938/AD7939 can have four pseudo differential pairs
(Pseudo Mode 1) or seven pseudo differential inputs (Pseudo
Mode 2) by setting the MODE0 and MODE1 bits in the control
register to 1, 0 and 1, 1, respectively. In the case of the four
pseudo differential pairs, VIN+ is connected to the signal source,
which must have an amplitude of VREF (or 2 × VREF depending
on the range chosen) to make use of the full dynamic range of
the part. A dc input is applied to the VIN pin. The voltage
applied to this input provides an offset from ground or a pseudo
ground for the VIN+ input. In the case of the seven pseudo
differential inputs, the seven analog input signals inputs are
referred to a dc voltage applied to VIN7.
The benefit of pseudo differential inputs is that they separate
the analog input signal ground from the ADC ground, allowing
dc common-mode voltages to be cancelled. Typically, this range
can extend from 0.3 V to +0.7 V when VDD = 3 V or 0.3 V to
+1.8 V when VDD = 5 V. Figure 30 shows a connection diagram
for pseudo differential mode.
VIN+
VIN–
VREF
AD7938/
AD7939*
*ADDITIONAL PINS OMITTED FOR CLARITY.
03715-
037
VREF p-p
0.47F
DC INPUT
VOLTAGE
+
Figure 30. Pseudo Differential Mode Connection Diagram
ANALOG INPUT SELECTION
As shown in Table 10, users can set up their analog input
configuration by setting the values in the MODE0 and MODE1
bits in the control register. Assuming the configuration has been
chosen, there are different ways of selecting the analog input to
be converted depending on the state of the SEQ and SHDW bits
in the control register.
Traditional Multichannel Operation (SEQ = SHDW = 0)
Any one of eight analog input channels or four pairs of channels
can be selected for conversion in any order by setting the SEQ
and SHDW bits in the control register to 0. The channel to be
converted is selected by writing to the address bits, ADD2 to
ADD0, in the control register to program the multiplexer prior
to the conversion. This mode of operation is that of a traditional
multichannel ADC where each data write selects the next
channel for conversion. Figure 31 shows a flowchart of this
mode of operation. The channel configurations are shown in
POWER ON
WRITE TO THE CONTROL REGISTER TO
SET UP OPERATING MODE, ANALOG INPUT
AND OUTPUT CONFIGURATION.
SET SEQ = SHDW = 0. SELECT THE DESIRED
CHANNEL TO CONVERT (ADD2 TO ADD0).
ISSUE CONVST PULSE TO INITIATE A CONVERSION
ON THE SELECTED CHANNEL.
INITIATE A READ CYCLE TO READ THE DATA
FROM THE SELECTED CHANNEL.
INITIATE A WRITE CYCLE TO SELECT THE NEXT
CHANNEL TO BE CONVERTED BY
CHANGING THE VALUES OF BITS ADD2 TO ADD0
IN THE CONTROL REGISTER. SEQ = SHDW = 0.
03715-
038
Figure 31. Traditional Multichannel Operation Flow Chart
相關(guān)PDF資料
PDF描述
AD7940BRM IC ADC 14BIT UNIPOLAR 8-MSOP
AD7942BRMZ-RL7 IC ADC 14BIT 250KSPS 10-MSOP
AD7944BCPZ IC ADC 14BIT 2.5MSPS 20LFCSP
AD7946BCPZRL7 IC ADC 14BIT 500KSPS 10-LFCSP
AD7948BN IC DAC 12BIT MULT PARALL 20-DIP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7938BCPZ-6 功能描述:IC ADC 12BIT 8CH 625KSPS 32LFCSP RoHS:是 類(lèi)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(lèi)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(lèi)型:2 個(gè)單端，單極
AD7938BCPZ-6REEL7 功能描述:IC ADC 12BIT 8CH 625KSPS 32LFCSP RoHS:是 類(lèi)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(lèi)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(lèi)型:2 個(gè)單端，單極
AD7938BCPZ-REEL7 功能描述:IC ADC 12BIT 8CH 1.5MSPS 32LFCSP RoHS:是 類(lèi)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):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(lèi)型:表面貼裝 封裝/外殼:24-SOIC（0.295"，7.50mm 寬） 供應(yīng)商設(shè)備封裝:24-SOIC 包裝:帶卷 (TR) 輸入數(shù)目和類(lèi)型:1 個(gè)單端，單極；1 個(gè)單端，雙極
AD7938BSU 制造商:Analog Devices 功能描述:
AD7938BSU-6 制造商:Analog Devices 功能描述:ADC Single SAR 625ksps 12-bit Parallel 32-Pin TQFP
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠(chǎng)商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*