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: 9/23页
文件大小: 334K
代理商: ADS5102IPFBR
ADS5102
ADS5103
SLAS351B – OCTOBER 2001 – REVISED DECEMBER 2001
17
www.ti.com
PRINCIPLES OF OPERATION
100 k
BG
1
F
AVDD
Figure 30. BG Reference Configuration
For systems that require more absolute accuracy or lower temperature coefficient drift than provided by the
internal VREF, an external voltage reference can be applied to the VREFB and VREFT inputs. To use external
reference, connect the PDREF pin to a logic high and this internally disconnects the VREF from the ADC. In
this mode it is also necessary to connect the BG and REFT pins together on the PWB. It is recommended to
use the input levels of VREFB = 0.75 V and VREFB = 1.25 V to achieve optimum ADC performance. It is also
recommended to apply a common-mode voltage to the input of 1 V.
clock input
The clock input is designed for 1.8 V or 3.3 V CMOS logic levels (depends on DRVDD) and it is recommended
to use standard CMOS logic levels as inputs. The logic threshold internally is set to DRVDD/2 or nominally 1.65
V. Since both edges of the clock are used in the switch capacitor architecture, it is important to provide a clock
with (ideally) a 50% duty cycle. The performance variation with clock duty cycle can be examined from
Figures 25, 26, 27 and 28.
Clock jitter is also important for performance of the ADC to be maintained. Any clock jitter appears as noise when
sampling input frequencies. Clock Jitter reduces the signal to noise ratio (SNR) and is more severe as the input
frequency increases. The theoretical SNR limits based on clock jitter can be calculated as follows:
Theoretical SNR
(clock jitter)
(dB)
+ 20 log
1
2
p
F
I
CLK
(jitter)
Where:
FI = Highest input frequency to the ADC in Hz
CLK(jitter) = the amount of jitter on the clock in sec
Therefore for a Nyquist frequency input of 32.5 MHz and a design trying to achieve the most available
performance from the ADS5102/3, the clock jitter must be less than 3.98 ps rms. In under sampling applications,
the same equations apply and clock jitter becomes more critical and may be the limiting factor in system
performance. The aperture jitter of the SHA also contributes to overall jitter. For worst case designs, the jitter
of clock and aperture can be considered to add in quadrature, i.e.
Total Jitter = Square root of ( CLKjitter2 + Aperturejitter 2)
The aperture jitter of the ADS5103 is 2 ps rms and at frequencies approaching Nyquist, the total jitter should
be accounted for.
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
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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