參數(shù)資料
型號(hào): ADC12138CIMSA
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: ADC
英文描述: Self-Calibrating 12-Bit Plus Sign Serial I/O A/D Converters with MUX and Sample/Hold
中文描述: 8-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO28
封裝: SSOP-28
文件頁數(shù): 30/41頁
文件大小: 1085K
代理商: ADC12138CIMSA
Application Hints
(Continued)
The Multiplexer assignment tables for the ADC12130/2/8
(Table 2 and Table 3) summarize the aforementioned func-
tions for the different versions of A/Ds.
2.1 Biasing for Various Multiplexer Configurations
Figure 11 is an example of biasing the device for
single-ended operation. The sign bit is always low. The digi-
tal output range is 0 0000 0000 0000 to 0 1111 1111 1111.
One LSB is equal to 1 mV (4.1V/4096 LSBs).
For pseudo-differential signed operation, the biasing circuit
shown in Figure 12 shows a signal AC coupled to the ADC.
This gives a digital output range of 4096 to +4095. With a
2.5V reference, as shown, 1 LSB is equal to 610 μV. Al-
though, the ADC is not production tested with a 2.5V refer-
ence, when V
A+
and V
D+
are +5.0V linearity error typically
will not change more than 0.1 LSB (see the curves in the
Typical Electrical Characteristics Section). With the ADC set
to an acquisition time of 10 clock periods, the input biasing
resistor needs to be 600
or less. Notice though that the in-
put coupling capacitor needs to be made fairly large to bring
down the high pass corner. Increasing the acquisition time to
34 clock periods (with a 5 MHz CCLK frequency) would al-
low the 600
to increase to 6k, which with a 1 μF coupling
capacitor would set the high pass corner at 26 Hz. Increas-
ing R, to 6k would allow R
2
to be 2k.
DS012079-38
FIGURE 11. Single-Ended Biasing
A
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ADC12138CIMSA/NOPB 功能描述:模數(shù)轉(zhuǎn)換器 - ADC SELF-CALIBR 12B PLUS SIGN SERIAL I/O ADC 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
ADC12138CIMSANOPB 制造商:TI 功能描述:Pb Free
ADC12138CIMSAX 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 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
ADC12138CIMSAX/NOPB 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 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
ADC12138CIN 制造商:Texas Instruments 功能描述:IC 12BIT ADC 12138 DIP28