- 您现在的位置：买卖IC网 > PDF目录165354 > ADS5103EVM (Texas Instruments, Inc.) 1.8-V ANALOG SUPPLY, 10-BIT, 65/40 MSPS ANALOG-TO-DIGITAL CONVERTERS WITH INTERNAL REFERENCE PDF资料下载
参数资料
| 型号： | ADS5103EVM |
| 厂商： | Texas Instruments, Inc. |
| 英文描述： | 1.8-V ANALOG SUPPLY, 10-BIT, 65/40 MSPS ANALOG-TO-DIGITAL CONVERTERS WITH INTERNAL REFERENCE |
| 中文描述： | 1.8 - V模拟电源，10位，65/40 MSPS的模拟到数字的，具有内部参考变换器 |
| 文件页数： | 10/23页 |
| 文件大小： | 334K |
| 代理商： | ADS5103EVM |
ADS5102
ADS5103
SLAS351B – OCTOBER 2001 – REVISED DECEMBER 2001
18
www.ti.com
PRINCIPLES OF OPERATION
digital outputs
The outputs of the ADS5102/3 are also CMOS and are programmable for either 3.3 V or 1.8 V CMOS logic
levels. This is controlled by the DRVDD supply. Either 3.3 V or 1.8 V can be applied to DRVDD with excellent
results. The output format is offset binary with D0 (LSB) and D9 (MSB). See Table 1 for output coding with a
differential input signal applied. There is a 5.5 clock latency from the sampling to valid data output on D0–D9.
The outputs can be placed into active mode by taking OE low or 3-state by taking OE high. The timing relations
between OE and output bus enable/disable times are shown in the timing diagram (refer to page 7). The
capacitive loading on the digital outputs is very important to achieve best performance. The total load
capacitance is typically made up of two sources, next stage input capacitance and PWB etch run capacitance.
The total capacitance of these two loads should be held to less than 15 pF. If for some reason, this cannot be
met, it is recommended to use logic buffers such as ‘244 placed physically very close to the ADC output. This
isolates the ADC output from the load capacitance and performance specs are achieved. Another technique
is to place a small resistor in series with the outputs. This resistance dampens the current spikes into the
capacitive loads and thus improve ADC performance. The value of this resistor varies with sampling rate but
generally 22
is a good value. Again this depends on the load capacitance.
The digital output of these devices is offset binary and follows the following format.
Table 1. Output Coding
ANALOG INPUT
SIGNAL VOLTAGE
STEP
DIGITAL OUTPUT CODE
ANALOG INPUT
IN +
SIGNAL VOLTAGE
IN –
STEP
MSB
LSB
REFT
REFB
1023
1
(REFT – REFB) / 2
512
1
0
511
0
1
REFB
REFT
0
Where there is either an internal voltage reference or an external voltage reference applied to the REFT and REFB pins.
driving the analog input
Since many real world signals are single ended and most modern high speed ADC’s employ differential inputs,
it is necessary in many cases to perform single ended to differential conversion prior to the ADC. Also, the ADC
performs optimally if a differential signal is applied to the inputs. In some cases, signal conditioning is required
in the form of the amplification or filtering. The two preferred techniques for driving the ADC input are: 1) With
an active amplifier specifically designed to drive ADC’s; 2) With an RF transformer.
driving the analog input with a differential amplifier
Texas Instruments has developed a family of high quality operational amplifiers that have been designed
specifically for driving the input stage of modern ADC’s. These devices allow for amplification and filtering prior
to the ADC. This stage can be used to set the maximum signal voltage to match the full scale input of the ADC.
The best solution for driving the ADS5102/3 ADC’s is the THS4501 amplifier. Figure 31 shows how to use this
device with a gain of 2. The ADC common mode output voltage can be directly connected to the op amp to
provide the proper levels. The THS4501 provides optimum matching of op amp output to the input of the
ADS5102/3. This configuration provides signal amplification, filtering, and single-ended to differential
conversion. It is recommended to provide de-coupling capacitors of 0.1
F and 0.001 F on the CML output.
This filters out any high frequency noise prior the ADC input.
相关PDF资料 |
PDF描述 |
|---|---|
| ADS5103IPFB | 1.8-V ANALOG SUPPLY, 10-BIT, 65/40 MSPS ANALOG-TO-DIGITAL CONVERTERS WITH INTERNAL REFERENCE |
| ADS5103IPFBR | 1.8-V ANALOG SUPPLY, 10-BIT, 65/40 MSPS ANALOG-TO-DIGITAL CONVERTERS WITH INTERNAL REFERENCE |
| ADS5413IPHP | SINGLE 12-BIT, 65-MSPS IF SAMPLING ANALOG-TO-DIGITAL CONVERTER |
| ADS6224IRGZ25 | 2-CH 12-BIT PROPRIETARY METHOD ADC, PARALLEL ACCESS, PQCC48 |
| ADS7812PB | 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDIP16 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ADS5103IPFB | 功能描述:模数转换器 - ADC 10 Bit 40MSPS 1.8V Int/Ext Ref w/Pwrdwn RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| ADS5103IPFBG4 | 功能描述:模数转换器 - ADC 10 Bit 40MSPS 1.8V Int/Ext Ref w/Pwrdwn RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| ADS5103IPFBR | 功能描述:模数转换器 - ADC 10 Bit 40MSPS 1.8V Int/Ext Ref w/Pwrdwn RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| ADS5103IPFBRG4 | 功能描述:模数转换器 - ADC 10 Bit 40MSPS 1.8V Int/Ext Ref w/Pwrdwn RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| ADS5120 | 制造商:TI 制造商全称:Texas Instruments 功能描述:8-Channel, 10-Bit, 40MSPS, 1.8V CMOS ANALOG-TO-DIGITAL CONVERTER |
发布紧急采购，3分钟左右您将得到回复。