FIGURE 2. AC-Coupled Input Configuration for a 2Vp-p Full-Scale Range and a Common-Mode Voltage, V
參數(shù)資料
型號: ADS828E
廠商: Texas Instruments
文件頁數(shù): 17/17頁
文件大小: 0K
描述: IC 10-BIT 75MHZ A/D 28-SSOP
產(chǎn)品培訓(xùn)模塊: Data Converter Basics
標(biāo)準(zhǔn)包裝: 50
系列: SpeedPlus™
位數(shù): 10
采樣率(每秒): 75M
數(shù)據(jù)接口: 并聯(lián)
轉(zhuǎn)換器數(shù)目: 1
功率耗散(最大): 340mW
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: 28-SSOP(0.209",5.30mm 寬)
供應(yīng)商設(shè)備封裝: 28-SSOP
包裝: 管件
輸入數(shù)目和類型: 2 個單端,單極;1 個差分,單極
產(chǎn)品目錄頁面: 888 (CN2011-ZH PDF)
ADS828
9
SBAS126A
FIGURE 2. AC-Coupled Input Configuration for a 2Vp-p Full-Scale Range and a Common-Mode Voltage, VCM, at +2.5V Derived
From The Internal Top (REFT) and Bottom Reference (REFB).
FIGURE 3. AC-Coupling the Dual Supply Amplifier OPA642 to the ADS828 for a 2Vp-p Full-Scale Input Range.
For applications requiring the driving amplifier to provide a
signal amplification, with a gain
≥ 5, consider using decom-
pensated voltage-feedback op amps, like the OPA643, or
current-feedback op amps like the OPA681 and OPA658.
DC-coupled with Level Shift
Several applications may require that the bandwidth of the
signal path include DC, in which case, the signal has to be
DC-coupled to the A/D converter. In order to accomplish
this, the interface circuit has to provide a DC level shift to
the analog input signal. The circuit shown in Figure 4
employs a dual op amp, A1, to drive the input of the
ADS828 and level shift the signal to be compatible with the
selected input range. With the RSEL pin tied to the supply
and the INT/EXT pin to ground, the ADS828 is configured
for a 2Vp-p input range and uses the internal references. The
complementary input (IN) may be appropriately biased
using the +2.5V common-mode voltage available at the
CM pin. One-half of amplifier A1 buffers the REFB pin and
drives the voltage divider R1, R2. Because of the op amp’s
noise gain of +2V/V, assuming RF = RIN, the common-mode
voltage (VCM) has to be re-scaled to +1.25. This results in
the correct DC level of +2.5V for the signal input (IN). Any
DC voltage differences between the IN and IN inputs of the
ADS828 effectively produces an offset, which can be cor-
rected for by adjusting the resistor values of the divider, R1
and R2. The selection criteria for a suitable op amp should
include the supply voltage, input bias current, output voltage
swing, distortion, and noise specification. Note that in this
example, the overall signal phase is inverted. To re-establish
the original signal polarity, it is always possible to inter-
change the IN and IN connections.
+V
IN
0V
–V
IN
OPA680
V
IN
R
F
402
1.0k
R
G
402
ADS828
R
S
50
10pF
0.1
F
IN
CM
INT/EXT
GND
REFT
+3.5V
1.0k
50
V
CM +2.5V
REFB
+1.5V
0.1
F
0.1
F
RSEL
+V
S
+5V
OPA642
V
IN
R
F
402
1.0k
R
G
402
ADS828
R
S
24.9
1.0k
100pF
0.1
F
0.1
F
IN
CM
REFB
+1.5V
INT/EXT
GND
REFT
+3.5V
RSEL
+V
S
+5V
–5V
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ADS828E 制造商:Texas Instruments 功能描述:IC 10BIT ADC 75MHZ SSOP28 828 制造商:Texas Instruments 功能描述:IC, 10BIT ADC, 75MHZ, SSOP28, 828
ADS828E 制造商:Texas Instruments 功能描述:IC 10-BIT ADC SAMPLING
ADS828E/1K 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 10-Bit 75 MSPS SE/Diff Int/Ext Ref RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
ADS828E/1KG4 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 10-Bit 75 MSPS SE/Diff Int/Ext Ref RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
ADS828EG4 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 10-Bit 75 MSPS SE/Diff Int/Ext Ref RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32