impedance driving the REF+
參數(shù)資料
型號: LTC2411IMS#TRPBF
廠商: Linear Technology
文件頁數(shù): 20/40頁
文件大?。?/td> 0K
描述: IC A/D CONV 24BIT MICRPWR 10MSOP
標(biāo)準(zhǔn)包裝: 2,500
位數(shù): 24
采樣率(每秒): 7.5
數(shù)據(jù)接口: MICROWIRE?,串行,SPI?
轉(zhuǎn)換器數(shù)目: 2
功率耗散(最大): 1mW
電壓電源: 單電源
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 10-TFSOP,10-MSOP(0.118",3.00mm 寬)
供應(yīng)商設(shè)備封裝: 10-MSOP
包裝: 帶卷 (TR)
輸入數(shù)目和類型: 1 個差分,雙極
LTC2411/LTC2411-1
27
user is thus advised to minimize the combined source
impedance driving the REF+ and REFpins rather than to
try to match it.
The magnitude of the dynamic reference current depends
upon the size of the very stable internal sampling capaci-
tors and upon the accuracy of the converter sampling
clock. The accuracy of the internal clock over the entire
temperature and power supply range is typical better than
1%. Such a specification can also be easily achieved by an
external clock. When relatively stable resistors (50ppm/
°C)
are used for the external source impedance seen by REF+
and REF, the expected drift of the dynamic current gain
error will be insignificant (about 1% of its value over the
entire temperature and voltage range). Even for the most
stringent applications, a one-time calibration operation
may be sufficient.
In addition to the reference sampling charge, the reference
pins ESD protection diodes have a temperature dependent
leakage current. This leakage current, nominally 1nA
(
±10nA max), results in a small gain error. A 100 source
resistance will create a 0.05
V typical and 0.5V maxi-
mum full-scale error.
Output Data Rate
When using its internal oscillator, the LTC2411 can pro-
duce up to 7.5 readings per second with a notch frequency
of 60Hz (FO = LOW) and 6.25 readings per second with a
notch frequency of 50Hz (FO = HIGH) and the LTC2411-1
can produce up to 6.8 readings per second with FO = LOW.
The actual output data rate will depend upon the length of
the sleep and data output phases which are controlled by
the user and which can be made insignificantly short.
When operated with an external conversion clock (FO
connected to an external oscillator), the LTC2411/LTC2411-
1 output data rate can be increased as desired. The
duration of the conversion phase is 20510/fEOSC. If fEOSC
= 153600Hz, the converter behaves as if the internal
oscillator is used and the notch is set at 60Hz. There is no
significant difference in the LTC2411/LTC2411-1 perfor-
mance between these two operation modes.
An increase in fEOSC over the nominal 153600Hz will
translate into a proportional increase in the maximum
output data rate. This substantial advantage is nevertheless
APPLICATIO S I FOR ATIO
WU
UU
accompanied by three potential effects, which must be
carefully considered.
First, a change in fEOSC will result in a proportional change
in the internal notch position and in a reduction of the
converter differential mode rejection at the power line
frequency. In many applications, the subsequent perfor-
mance degradation can be substantially reduced by rely-
ing upon the LTC2411/LTC2411-1’s exceptional common
mode rejection and by carefully eliminating common
mode to differential mode conversion sources in the input
circuit. The user should avoid single-ended input filters
and should maintain a very high degree of matching and
symmetry in the circuits driving the IN+ and INpins.
Second, the increase in clock frequency will increase
proportionally the amount of sampling charge transferred
through the input and the reference pins. If large external
input and/or reference capacitors (CIN, CREF) are used, the
previous section provides formulae for evaluating the
effect of the source resistance upon the converter perfor-
mance for any value of fEOSC. If small external input and/
or reference capacitors (CIN, CREF) are used, the effect of
the external source resistance upon the LTC2411/
LTC2411-1 typical performance can be inferred from
Figures 13, 14 and 17 in which the horizontal axis is scaled
by 153600/fEOSC.
Third, an increase in the frequency of the external oscilla-
tor above 460800Hz (a more than 3
×increaseintheoutput
data rate) will start to decrease the effectiveness of the
internal autocalibration circuits. This will result in a progres-
sive degradation in the converter accuracy and linearity.
Typical measured performance curves for output data rates
up to 100 readings per second are shown in Figures 20 to
27. In order to obtain the highest possible level of accuracy
from this converter at output data rates above 20 readings
per second, the user is advised to maximize the power
supply voltage used and to limit the maximum ambient
operating temperature. In certain circumstances, a reduc-
tion of the differential reference voltage may be beneficial.
Input Bandwidth
The combined effect of the internal sinc4 digital filter and
of the analog and digital autocalibration circuits deter-
mines the LTC2411/LTC2411-1 input bandwidth. When
相關(guān)PDF資料
PDF描述
MS27472E8F35PA CONN RCPT 6POS WALL MNT W/PINS
MS27467T11F98PA CONN PLUG 6POS STRAIGHT W/PINS
MS27473E10B35PB CONN PLUG 13POS STRAIGHT W/PINS
VI-J3J-MX-S CONVERTER MOD DC/DC 36V 75W
MS27472T20A16P CONN RCPT 16POS WALL MT W/PINS
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC2412CGN 功能描述:IC ADC 2CH DIFF-IN 24BIT 16SSOP 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(biāo)準(zhǔn)包裝:1,000 系列:- 位數(shù):16 采樣率(每秒):45k 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:2 功率耗散(最大):315mW 電壓電源:模擬和數(shù)字 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:28-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:28-SOIC W 包裝:帶卷 (TR) 輸入數(shù)目和類型:2 個單端,單極
LTC2412CGN#PBF 功能描述:IC ADC 2CH DIFF-IN 24BIT 16SSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:1 系列:microPOWER™ 位數(shù):8 采樣率(每秒):1M 數(shù)據(jù)接口:串行,SPI? 轉(zhuǎn)換器數(shù)目:1 功率耗散(最大):- 電壓電源:模擬和數(shù)字 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:24-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:24-VQFN 裸露焊盤(4x4) 包裝:Digi-Reel® 輸入數(shù)目和類型:8 個單端,單極 產(chǎn)品目錄頁面:892 (CN2011-ZH PDF) 其它名稱:296-25851-6
LTC2412CGN#PBF 制造商:Linear Technology 功能描述:IC, ADC, 24BIT, SSOP-16
LTC2412CGN#TR 功能描述:IC CONV A/D 24B 2CH DIFF 16-SSOP 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(biāo)準(zhǔn)包裝:1,000 系列:- 位數(shù):16 采樣率(每秒):45k 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:2 功率耗散(最大):315mW 電壓電源:模擬和數(shù)字 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:28-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:28-SOIC W 包裝:帶卷 (TR) 輸入數(shù)目和類型:2 個單端,單極
LTC2412CGN#TRPBF 功能描述:IC ADC 2CH DIFF-IN 24BIT 16SSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:1,000 系列:- 位數(shù):16 采樣率(每秒):45k 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:2 功率耗散(最大):315mW 電壓電源:模擬和數(shù)字 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:28-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:28-SOIC W 包裝:帶卷 (TR) 輸入數(shù)目和類型:2 個單端,單極