- 您现在的位置：买卖IC网 > PDF目录165354 > ADS5102IPFBR (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： | ADS5102IPFBR |
| 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： | 8/23页 |
| 文件大小： | 334K |
| 代理商： | ADS5102IPFBR |
ADS5102
ADS5103
SLAS351B – OCTOBER 2001 – REVISED DECEMBER 2001
16
www.ti.com
PRINCIPLES OF OPERATION
analog input sample and hold amplifier circuit
The sample and hold amplifier is implemented using switch capacitor techniques. A simplified functional block
diagram is shown in Figure 29. The SHA is in sample mode when CLK is high and in hold mode when CLK is
low. In sample mode, the input switches, P1, are closed and the differential input signal is sampled onto caps
Cs. An internal common-mode voltage is applied to the sampling caps (Cs) when the two P1P switches are
closed. As the CLK falling edge occurs, the SHA is now placed into hold or amplification mode. In this mode,
P1 switches are now opened and switches P2 are closed. This is the amplification state and the signal is
transferred to the output of the amplifier with a nominal gain of 1. CL of Figure 29 represents the load
capacitance of the following stage. R-C values of the input determine the analog input bandwidth of the SHA
(and therefore the whole ADC) which is 950 MHz for the ADS5102/3. This wide bandwidth assures no distortion
to the Nyquist frequency of 32.5 MHz. In under sampling applications, it is common to require the analog input
bandwidth to be 5 times greater than the IF Nyquist frequency. As such, the ADS5102/3 supports IF frequencies
approaching 200 MHz in under sampling applications.
_
+ _
+
P1
CL
CI
P1P
VC
CS
P2
P1
VINP
VIN
Figure 29. Simplified Functional Block Diagram
Because the input to the sample and hold amplifier is a switched capacitor circuit, the input resistance is dynamic
and based on the sampling rate of the converter. The impedance of each input is defined by the equation:
Z
I +
1
F
Cs
Where:
Cs = Sampling capacitor = 0.4 pF typical
F = CLK frequency in Hz
The key for selecting an amplifier to correctly drive the ADS5102/3 is to ensure that the output frequency of the
amplifier is much lower than the input impedance of the ADS5102/3, which at 65 MSPS is 38.46 k
. For system
accuracy comparable to 1 LSB, this means selecting an amplifier with output impedance of ~ 31
for sampling
rates of 65 MSPS.
reference configurations
The ADS5102/3 provides an internal voltage reference which should be suitable for most 10 bit systems. The
typical full scale voltage for the device is determined by VFS = VREFT – VREFB. Since the input is fully
differential, the full scale input is twice the single ended value or 1 V differential. It is recommended to externally
de-couple both VREFT and VREFB with a 0.1
F capacitor to bypass all high frequency noise to ground. It is
necessary to connect BG and AVDD with a 100 k resistor and decouple with a 1 F capacitor to AGND (refer
to Figure 30 for correct configuration).
相关PDF资料 |
PDF描述 |
|---|---|
| ADS5103 | "10 Bit |
| ADS5103CPFB | 1.8-V ANALOG SUPPLY, 10-BIT, 65/40 MSPS ANALOG-TO-DIGITAL CONVERTERS WITH INTERNAL REFERENCE |
| ADS5103CPFBR | 1.8-V ANALOG SUPPLY, 10-BIT, 65/40 MSPS ANALOG-TO-DIGITAL CONVERTERS WITH INTERNAL REFERENCE |
| ADS5103EVM | 1.8-V ANALOG SUPPLY, 10-BIT, 65/40 MSPS ANALOG-TO-DIGITAL CONVERTERS WITH INTERNAL REFERENCE |
| ADS5103IPFB | 1.8-V ANALOG SUPPLY, 10-BIT, 65/40 MSPS ANALOG-TO-DIGITAL CONVERTERS WITH INTERNAL REFERENCE |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ADS5102IPFBRG4 | 功能描述:模数转换器 - ADC 10 Bit 65MSPS 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 |
| ADS5103 | 制造商:TI 制造商全称:Texas Instruments 功能描述:1.8-V ANALOG SUPPLY, 10-BIT, 65/40 MSPS ANALOG-TO-DIGITAL CONVERTERS WITH INTERNAL REFERENCE |
| ADS5103CPFB | 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 |
| ADS5103CPFBG4 | 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 |
| ADS5103CPFBR | 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 |
发布紧急采购，3分钟左右您将得到回复。