参数资料
型号: LTC2258CUJ-12#PBF
厂商: Linear Technology
文件页数: 17/34页
文件大小: 0K
描述: IC ADC 12BIT 65MSPS 1.8V 40-QFN
产品培训模块: LTC2262 - Ultra Low Power High Speed ADCs
标准包装: 61
位数: 12
采样率(每秒): 65M
数据接口: 并联,串行,SPI
转换器数目: 1
功率耗散(最大): 89mW
电压电源: 单电源
工作温度: 0°C ~ 70°C
安装类型: 表面贴装
封装/外壳: 40-WFQFN 裸露焊盘
供应商设备封装: 40-QFN(6x6)
包装: 管件
输入数目和类型: 1 个差分
配用: DC718C-ND - DEMO QUIKEVAL-II DATA
LTC2258-12
LTC2257-12/LTC2256-12
24
225812fd
For more information www.linear.com/LTC2258-12
Digital Output Randomizer
Interference from the A/D digital outputs is sometimes
unavoidable.Digitalinterferencemaybefromcapacitiveor
inductive coupling or coupling through the ground plane.
Even a tiny coupling factor can cause unwanted tones
in the ADC output spectrum. By randomizing the digital
output before it is transmitted off chip, these unwanted
tones can be randomized which reduces the unwanted
tone amplitude.
The digital output is “randomized” by applying an
exclusive-OR logic operation between the LSB and all
other data output bits. To decode, the reverse opera-
tion is applied—an exclusive-OR operation is applied
between the LSB and all other bits. The LSB, OF and
CLKOUT outputs are not affected. The output random-
izer is enabled by serially programming mode control
register A4.
Alternate Bit Polarity
Another feature that reduces digital feedback on the circuit
board is the alternate bit polarity mode. When this mode
is enabled, all of the odd bits (D1, D3, D5, D7, D9, D11)
are inverted before the output buffers. The even bits (D0,
D2, D4, D6, D8, D10), OF and CLKOUT are not affected.
This can reduce digital currents in the circuit board ground
plane and reduce digital noise, particularly for very small
analog input signals.
When there is a very small signal at the input of the A/D
thatiscenteredaroundmidscale,thedigitaloutputstoggle
between mostly 1s and mostly 0s. This simultaneous
switchingofmostofthebitswillcauselargecurrentsinthe
ground plane. By inverting every other bit, the alternate bit
polarity mode makes half of the bits transition high while
half of the bits transition low. To first order, this cancels
currentflowinthegroundplane,reducingthedigitalnoise.
applicaTions inForMaTion
CLKOUT
OF
D11/D0
D10/D0
D2/D0
D1/D0
D0
225812 F15
OF
D11
D10
D2
D1
D0
RANDOMIZER
ON
D11
FPGA
PC BOARD
D10
D2
D1
D0
225812 F15
D0
D1/D0
D2/D0
D10/D0
D11/D0
OF
CLKOUT
LTC2258-12
Figure 15. Functional Equivalent of Digital Output Randomizer
Figure 16. Unrandomizing a Randomized Digital
Output Signal
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LTC2258CUJ-12-TRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:12-Bit, 65/40/2 5Msps Ultralow Power 1.8V ADCs
LTC2258CUJ-14#PBF 功能描述:IC ADC 14BIT 65MSPS 1.8V 40-QFN RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 其它有关文件:TSA1204 View All Specifications 标准包装:1 系列:- 位数:12 采样率(每秒):20M 数据接口:并联 转换器数目:2 功率耗散(最大):155mW 电压电源:模拟和数字 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-TQFP 供应商设备封装:48-TQFP(7x7) 包装:Digi-Reel® 输入数目和类型:4 个单端,单极;2 个差分,单极 产品目录页面:1156 (CN2011-ZH PDF) 其它名称:497-5435-6
LTC2258CUJ-14#TRPBF 功能描述:IC ADC 14BIT 65MSPS 1.8V 40-QFN RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1 系列:- 位数:14 采样率(每秒):83k 数据接口:串行,并联 转换器数目:1 功率耗散(最大):95mW 电压电源:双 ± 工作温度:0°C ~ 70°C 安装类型:通孔 封装/外壳:28-DIP(0.600",15.24mm) 供应商设备封装:28-PDIP 包装:管件 输入数目和类型:1 个单端,双极
LTC2258CUJ-14-PBF 制造商:LINER 制造商全称:Linear Technology 功能描述:14-Bit, 65/40/25Msps Ultralow Power 1.8V ADCs
LTC2258CUJ-14-TRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:14-Bit, 65/40/25Msps Ultralow Power 1.8V ADCs