參數資料
型號: ADS830
英文描述: 8-Bit, 60MHz Sampling ANALOG-TO-DIGITAL CONVERTER
中文描述: 8位,60MHz時采樣模擬數字轉換器
文件頁數: 8/11頁
文件大?。?/td> 177K
代理商: ADS830
8
ADS830
OPA642
V
IN
R
F
402
1k
R
G
402
ADS830
R
S
24.9
1k
47pF
0.1μF
0.1
μ
F
IN
IN
CM
REFB
+2.0V
INT/EXT
GND
REFT
+3.0V
RSEL
+V
S
+5V
+5V
–5V
ately biased using the +2.5V common-mode voltage avail-
able at the CM pin. One-half of the amplifier (OPA2681)
buffers the REFB pin and drives the voltage divider R
1
, R
2
.
Because of the op amp’s noise gain of +2V/V, assuming
R
F
= R
IN
, the common-mode voltage (V
CM
) has to be re-
scaled to +1.25V, resulting in the correct DC level of +2.5V
for the signal input (IN). Any DC voltage differences be-
tween the IN and IN inputs of the ADS830 effectively
produce an offset, which can be corrected for by adjusting
the resistor values of the divider, R
1
and R
2
. 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 interchange the IN and IN
connections.
FIGURE 3. AC-Coupling the Dual Supply Amplifier OPA642 to the ADS830 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, such as the OPA643, or
current feedback op amps OPA681 and OPA658.
DC-Coupled with Level Shift
Several applications may require that the bandwidth of the
signal path includes 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
ADS830 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 ADS830 is
configured for a 2Vp-p input range and uses the internal
references. The complementary input (IN) may be appropri-
+V
IN
0V
–V
IN
OPA681
V
IN
R
F
402
1k
R
G
402
ADS830
R
S
39
47pF
0.1μF
IN
IN
CM
INT/EXT
GND
REFT
+3.0V
1k
V
CM
= +2.5V
DC
REFB
+2.0V
0.1
μ
F
0.1μF
RSEL
+V
S
+5V
+5V
FIGURE 2. AC-Coupled Input Configuration for a 2Vp-p Full-Scale Range and a Common-Mode Voltage, V
CM
, at +2.5V
Derived from the Internal Top (REFT) and Bottom Reference (REFB). The OPA680 can be used in place of the
OPA681 if a voltage feedback amplifier is preferred.
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ADS830E 功能描述:模數轉換器 - ADC 8-Bit 60 MSPS SE/Diff Inputs RoHS:否 制造商:Texas Instruments 通道數量:2 結構:Sigma-Delta 轉換速率: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 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
ADS830E/2K5 功能描述:模數轉換器 - ADC 8-Bit 60 MSPS SE/Diff Inputs RoHS:否 制造商:Texas Instruments 通道數量:2 結構:Sigma-Delta 轉換速率: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 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
ADS830E/2K5G4 功能描述:模數轉換器 - ADC 8-Bit 60 MSPS SE/Diff Inputs RoHS:否 制造商:Texas Instruments 通道數量:2 結構:Sigma-Delta 轉換速率: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 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
ADS830EG4 功能描述:模數轉換器 - ADC 8-Bit 60 MSPS SE/Diff Inputs RoHS:否 制造商:Texas Instruments 通道數量:2 結構:Sigma-Delta 轉換速率: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 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
ADS831 制造商:BB 制造商全稱:BB 功能描述:8-Bit, 80MHz Sampling ANALOG-TO-DIGITAL CONVERTER