Figure 11. Transformer Driven ENC+/" />
參數(shù)資料
型號: LTC2223CUK#PBF
廠商: Linear Technology
文件頁數(shù): 14/28頁
文件大?。?/td> 0K
描述: IC ADC 12BIT 80MSPS SAMPLE 48QFN
標準包裝: 52
位數(shù): 12
采樣率(每秒): 80M
數(shù)據(jù)接口: 并聯(lián)
轉(zhuǎn)換器數(shù)目: 1
功率耗散(最大): 406mW
電壓電源: 單電源
工作溫度: 0°C ~ 70°C
安裝類型: 表面貼裝
封裝/外殼: 48-WFQFN 裸露焊盤
供應商設備封裝: 48-QFN-EP(7x7)
包裝: 管件
輸入數(shù)目和類型: 1 個單端,雙極; 1 個差分,雙極
產(chǎn)品目錄頁面: 1349 (CN2011-ZH PDF)
LTC2222/LTC2223
21
22223fb
APPLICATIONS INFORMATION
Figure 11. Transformer Driven ENC+/ENC
In applications where jitter is critical (high input frequen-
cies) take the following into consideration:
1. Differential drive should be used.
2. Use as large an amplitude as possible; if transformer
coupled use a higher turns ratio to increase the
amplitude.
3. If the ADC is clocked with a sinusoidal signal, lter the
encode signal to reduce wideband noise.
4. Balance the capacitance and series resistance at both
encode inputs so that any coupled noise will appear at
both inputs as common mode noise. The encode inputs
have a common mode range of 1.1V to 2.5V. Each input
may be driven from ground to VDD for single-ended
drive.
Maximum and Minimum Encode Rates
The maximum encode rate for the LTC2222/LTC2223 is
105Msps (LTC2222) and 80Msps (LTC2223). For the
ADC to operate properly, the encode signal should have a
50% (±5%) duty cycle. Each half cycle must have at least
4.5ns (LTC2222) or 5.9ns (LTC2223) for the ADC internal
circuitry to have enough settling time for proper operation.
Achieving a precise 50% duty cycle is easy with differential
sinusoidal drive using a transformer or using symmetric
differential logic such as PECL or LVDS.
An optional clock duty cycle stabilizer circuit can be used
if the input clock has a non 50% duty cycle. This circuit
uses the rising edge of the ENC+ pin to sample the analog
input. The falling edge of ENC+ is ignored and the internal
falling edge is generated by a phase-locked loop. The input
clock duty cycle can vary from 20% to 80% and the clock
duty cycle stabilizer will maintain a constant 50% internal
duty cycle. If the clock is turned off for a long period of
time, the duty cycle stabilizer circuit will require a hundred
clock cycles for the PLL to lock onto the input clock. To
use the clock duty cycle stabilizer, the MODE pin should be
connected to 1/3VDD or 2/3VDD using external resistors.
Input Range
The input range can be set based on the application.
The 2V input range will provide the best signal-to-noise
performance while maintaining excellent SFDR. The 1V
input range will have better SFDR performance, but the
SNR will degrade by 5dB. See the Typical Performance
Characteristics section.
Driving the Encode Inputs
The noise performance of the LTC2222/LTC2223 can
depend on the encode signal quality as much as on the
analog input. The ENC+/ENCinputs are intended to be
driven differentially, primarily for noise immunity from
common mode noise sources. Each input is biased
through a 6k resistor to a 1.6V bias. The bias resistors
set the DC operating point for transformer coupled drive
circuits and can set the logic threshold for single-ended
drive circuits.
Any noise present on the encode signal will result in ad-
ditional aperture jitter that will be RMS summed with the
inherent ADC aperture jitter.
VDD
LTC2222/LTC2223
22223 F11
VDD
ENC–
ENC+
1.6V BIAS
1:4
0.1μF
CLOCK
INPUT
50Ω
6k
TO INTERNAL
ADC CIRCUITS
相關(guān)PDF資料
PDF描述
MS3101A16S-5P CONN RCPT 3POS FREE HNG W/PINS
LTC2291IUP#PBF IC ADC DUAL 12BIT 25MSPS 64QFN
AD7892ARZ-3 IC ADC 12BIT LP 600KSPS 24SOIC
MS3100A20-6S CONN RCPT 3POS WALL MNT W/SCKT
LTC2280IUP#PBF IC ADC DUAL 10BIT 105MSPS 64-QFN
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC2223IUK 功能描述:IC ADC 12BIT 80MSPS SAMPLE 48QFN RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標準包裝:1 系列:- 位數(shù):14 采樣率(每秒):83k 數(shù)據(jù)接口:串行,并聯(lián) 轉(zhuǎn)換器數(shù)目:1 功率耗散(最大):95mW 電壓電源:雙 ± 工作溫度:0°C ~ 70°C 安裝類型:通孔 封裝/外殼:28-DIP(0.600",15.24mm) 供應商設備封裝:28-PDIP 包裝:管件 輸入數(shù)目和類型:1 個單端,雙極
LTC2223IUK#PBF 功能描述:IC ADC 12BIT 80MSPS SAMPLE 48QFN RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 其它有關(guān)文件:TSA1204 View All Specifications 標準包裝:1 系列:- 位數(shù):12 采樣率(每秒):20M 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:2 功率耗散(最大):155mW 電壓電源:模擬和數(shù)字 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:48-TQFP 供應商設備封裝:48-TQFP(7x7) 包裝:Digi-Reel® 輸入數(shù)目和類型:4 個單端,單極;2 個差分,單極 產(chǎn)品目錄頁面:1156 (CN2011-ZH PDF) 其它名稱:497-5435-6
LTC2223IUK#TR 功能描述:IC ADC 12BIT 80MSPS SAMPLE 48QFN RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標準包裝:1 系列:- 位數(shù):14 采樣率(每秒):83k 數(shù)據(jù)接口:串行,并聯(lián) 轉(zhuǎn)換器數(shù)目:1 功率耗散(最大):95mW 電壓電源:雙 ± 工作溫度:0°C ~ 70°C 安裝類型:通孔 封裝/外殼:28-DIP(0.600",15.24mm) 供應商設備封裝:28-PDIP 包裝:管件 輸入數(shù)目和類型:1 個單端,雙極
LTC2223IUK#TRPBF 功能描述:IC ADC 12BIT 80MSPS SAMPLE 48QFN RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:2,500 系列:- 位數(shù):12 采樣率(每秒):3M 數(shù)據(jù)接口:- 轉(zhuǎn)換器數(shù)目:- 功率耗散(最大):- 電壓電源:- 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:SOT-23-6 供應商設備封裝:SOT-23-6 包裝:帶卷 (TR) 輸入數(shù)目和類型:-
LTC2223UK 制造商:LINER 制造商全稱:Linear Technology 功能描述:12-Bit,105Msps/80Msps ADCs