參數資料
型號: LTC2492CDE
廠商: LINEAR TECHNOLOGY CORP
元件分類: ADC
英文描述: 4-CH 24-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PDSO14
封裝: 4 X 3 MM, PLASTIC, MO-229WGED-3, QFN-14
文件頁數: 28/36頁
文件大?。?/td> 652K
代理商: LTC2492CDE
LTC2492
2492fa
applicaTions inFormaTion
Easy Drive ADCs Simplify Measurement of High
Impedance Sensors
Delta-SigmaADCs,withtheirhighaccuracyandhighnoise
immunity, are ideal for directly measuring many types
of sensors. Nevertheless, input sampling currents can
overwhelm high source impedances or low-bandwidth,
micropower signal conditioning circuits. The LTC2492
solves this problem by balancing the input currents, thus
simplifying or eliminating the need for signal conditioning
circuits.
A common application for a delta-sigma ADC is thermistor
measurement.Figure38showstwoexamplesofthermistor
digitization benefiting from the Easy Drive technology.
The first circuit (applied to input channels CH0 and CH1)
uses balanced reference resistors in order to balance the
common mode input/reference voltage and balance the
differential input source resistance. If reference resistors
R1 and R4 are exactly equal, the input current is zero and
no errors result. If these resistors have a 1% tolerance,
the maximum error in measured resistance is 1.6
Ω due
to a shift in common mode voltage; far less than the 1%
error of the reference resistors themselves. No amplifier
is required, making this an ideal solution in micropower
applications.
Easy Drive also enables very low power, low bandwidth
amplifiers to drive the input to the LTC2492. As shown
in Figure 38, CH2 is driven by the LT1494. The LT1494
has excellent DC specs for an amplifier with 1.5A supply
current (the maximum offset voltage is 150V and the
open loop gain is 100,000). Its 2kHz bandwidth makes
it unsuitable for driving conventional delta sigma ADCs.
Addinga1k
Ω,0.1Ffiltersolvesthisproblembyproviding
achargereservoirthatsuppliestheLTC2492instantaneous
current, while the 1k resistor isolates the capacitive load
from the LT1494.
Conventional delta sigma ADCs input sampling current
lead to DC errors as a result of incomplete settling in the
external RC network.
The Easy Drive technology cancels the differential input
current. By balancing the negative input (CH3) with a 1k
Ω,
0.1F network errors due to the common mode input
current are cancelled.
相關PDF資料
PDF描述
LTC2492IDE 4-CH 24-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PDSO14
LTC2492IDE#TR 4-CH 24-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PDSO14
LTC2494CUHF 16-CH 16-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PQCC38
LTC2494IUHF#TR 16-CH 16-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PQCC38
LTC2494IUHF 16-CH 16-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PQCC38
相關代理商/技術參數
參數描述
LTC2492CDE#PBF 功能描述:IC ADC 24BIT DELTA SIG 14-DFN RoHS:是 類別:集成電路 (IC) >> 數據采集 - 模數轉換器 系列:- 標準包裝:1 系列:microPOWER™ 位數:8 采樣率(每秒):1M 數據接口:串行,SPI? 轉換器數目:1 功率耗散(最大):- 電壓電源:模擬和數字 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 供應商設備封裝:24-VQFN 裸露焊盤(4x4) 包裝:Digi-Reel® 輸入數目和類型:8 個單端,單極 產品目錄頁面:892 (CN2011-ZH PDF) 其它名稱:296-25851-6
LTC2492CDE#TRPBF 功能描述:IC ADC 24BIT DELTA SIG 14-DFN RoHS:是 類別:集成電路 (IC) >> 數據采集 - 模數轉換器 系列:- 標準包裝:2,500 系列:- 位數:16 采樣率(每秒):15 數據接口:MICROWIRE?,串行,SPI? 轉換器數目:1 功率耗散(最大):480µW 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:38-WFQFN 裸露焊盤 供應商設備封裝:38-QFN(5x7) 包裝:帶卷 (TR) 輸入數目和類型:16 個單端,雙極;8 個差分,雙極 配用:DC1011A-C-ND - BOARD DELTA SIGMA ADC LTC2494
LTC2492IDE#PBF 功能描述:IC ADC 24BIT DELTA SIG 14-DFN RoHS:是 類別:集成電路 (IC) >> 數據采集 - 模數轉換器 系列:- 標準包裝:1 系列:microPOWER™ 位數:8 采樣率(每秒):1M 數據接口:串行,SPI? 轉換器數目:1 功率耗散(最大):- 電壓電源:模擬和數字 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 供應商設備封裝:24-VQFN 裸露焊盤(4x4) 包裝:Digi-Reel® 輸入數目和類型:8 個單端,單極 產品目錄頁面:892 (CN2011-ZH PDF) 其它名稱:296-25851-6
LTC2492IDE#TRPBF 功能描述:IC ADC 24BIT DELTA SIG 14-DFN RoHS:是 類別:集成電路 (IC) >> 數據采集 - 模數轉換器 系列:- 標準包裝:1,000 系列:- 位數:16 采樣率(每秒):45k 數據接口:串行 轉換器數目:2 功率耗散(最大):315mW 電壓電源:模擬和數字 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) 供應商設備封裝:28-SOIC W 包裝:帶卷 (TR) 輸入數目和類型:2 個單端,單極
LTC2493CDE#PBF 功能描述:IC ADC 24BIT DELTA SIG 14-DFN RoHS:是 類別:集成電路 (IC) >> 數據采集 - 模數轉換器 系列:- 標準包裝:2,500 系列:- 位數:16 采樣率(每秒):15 數據接口:MICROWIRE?,串行,SPI? 轉換器數目:1 功率耗散(最大):480µW 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:38-WFQFN 裸露焊盤 供應商設備封裝:38-QFN(5x7) 包裝:帶卷 (TR) 輸入數目和類型:16 個單端,雙極;8 個差分,雙極 配用:DC1011A-C-ND - BOARD DELTA SIGMA ADC LTC2494