參數(shù)資料
型號(hào): AD7707EB
廠商: Analog Devices, Inc.
英文描述: 3 V/5 V 610 V Input Range 1 mW 3-Channel 16-Bit Sigma-Delta ADC(316.51 k)
中文描述: 3伏/ 5伏610 V輸入范圍1毫瓦3通道16位Σ-Δ模數(shù)轉(zhuǎn)換器(316.51十一)
文件頁數(shù): 37/40頁
文件大?。?/td> 316K
代理商: AD7707EB
REV. A
AD7707
–37–
Accommodating Various High Level Input Ranges
The high level input channel, AIN3 can accommodate input signals from –11 V to +30 V on its input. This is achieved using
on-chip thin film resistors that map the signal on AIN3 into a usable range for the AD7707. The input structure is arranged
so that the sigma-delta converter sees the same impedance at its AIN(+) and AIN(–) inputs. The signal on the AIN3 input is
referenced to the HICOM input and the VBIAS signal is used to adjust the common-mode voltage at the modulator input.
In normal 5 V operation VBIAS is normally connected to 2.5 V and HICOM is connected to AGND. This arrangement
ensures that the voltages seen at the modulator input are within the common-mode range of the buffer.
The differential voltage, AIN, seen by the AD7707 when using the high level input channel is the difference between AIN3(+)
and AIN3(–) as shown in Figure 30 and must remain within the absolute common-mode range of the modulator.
AIN
3(+)
=
(
AIN
3 + 6
×
VBIAS+ V
(
HICOM
))
/
8
AIN
3(–)
=
0.75
×
VBIAS +
0.25
V
(
HICOM
)
AIN = (AIN3 – V
(
HICOM
))/8
AIN
5k
V
30k
V
15k
V
5k
V
AIN3
VBIAS
HICOM
AIN3(+)
AIN3(–)
30k
V
MUX
Figure 30. AIN3, High Level Input Channel Structure
The VBIAS and HICOM inputs are used to tailor the input range on the high level input channel to suit a variety of input
ranges. The following table applies for operation with AV
DD
= 5 V, and REF(+) – REF(–) = 2.5 V.
Table XIX
AIN3 RANGE
VBIAS
HICOM
GAIN
BUF/UNBUF
AIN RANGE
±
10 V
±
5 V
0 V to 10 V
0 V to 20 V
2.5 V
2.5 V
2.5 V
AGND
2.5 V
2.5 V
AGND
AGND
AGND
AGND
AGND
2.5 V
2
4
2
1
1
2
BUF/UNBUF
BUF/UNBUF
BUF/UNBUF
UNBUF
UNBUF
BUF/UNBUF
1.875 V
±
1.25 V
1.875 V
±
0.625 V
1.875 V to 3.125 V
0 V to 2.5 V
1.875 V to 4.375 V
2.5 V
±
0.9375 V
–5 V to +10 V
The following table applies for operation with AV
DD
= 3 V, and REF(+) – REF(–) = 1.25 V.
Table XX
AIN3 RANGE
VBIAS
HICOM
GAIN
BUF/UNBUF
AIN RANGE
±
5 V
0 V to 10 V
–5 V to +10 V
–7.5 V to +10 V
±
10 V
1.25 V
1.25 V
1.25 V
1.25 V
1.666 V
AGND
AGND
2.5 V
0
AGND
2
1
1
1
1
UNBUF
UNBUF
UNBUF
UNBUF
UNBUF
0.9375 V
±
0.625 V
0.9375 V to 2.1875 V
1.5625 V
±
0.9375 V
0 V to 2.1875 V
1.25 V
±
1.25 V
Typical Input Currents
When using the high level input channel, power dissipation is determined by the currents flowing in the AIN3, VBIAS and
HICOM inputs. The voltage level applied to these inputs determines whether the external source driving these inputs needs
to sink of source current. The following table shows the currents associated with the
±
10 V input range. These inputs should
be driven from a low impedance source in all applications to prevent significant gain errors being introduced.
Table XXI
AIN3
VBIAS
HICOM
I (AIN3)
I (VBIAS)
I (HICOM)
–10 V
0 V
+10 V
2.5 V
2.5 V
2.5 V
AGND
AGND
AGND
–354
μ
A
–62
μ
A
229
μ
A
500
μ
A
250
μ
A
0
–146
μ
A
–188
μ
A
–229
μ
A
相關(guān)PDF資料
PDF描述
AD7708BR Shaft; Style: 2 - light; Applicable Model: LE-P / LEL-W
AD7708BRU 8-/10-Channel, Low Voltage, Low Power, ADCs
AD7708 8-/10-Channel, Low Voltage, Low Power, ADCs
AD7718 8-/10-Channel, Low Voltage, Low Power, ADCs
AD7718BR 8-/10-Channel, Low Voltage, Low Power, ADCs
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7708 制造商:AD 制造商全稱:Analog Devices 功能描述:8-/10-Channel, Low Voltage, Low Power, ADCs
AD7708BR 功能描述:IC ADC 16BIT R-R 8/10CH 28-SOIC 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(gè)單端,單極
AD7708BR-REEL 功能描述:IC ADC 16BIT R-R 8/10CH 28-SOIC 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(gè)單端,單極
AD7708BR-REEL7 功能描述:IC ADC 16BIT R-R 8/10CH 28-SOIC 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(gè)單端,單極
AD7708BRU 功能描述:IC ADC 16BIT R-R 8/10CH 28-TSSOP 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(gè)單端,單極