參數(shù)資料
型號(hào): LTC2488CDE
廠商: LINEAR TECHNOLOGY CORP
元件分類: ADC
英文描述: 4-CH 16-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PQCC14
封裝: 4 X 3 MM, PLASTIC, MO-229WGED-3, QFN-14
文件頁(yè)數(shù): 18/28頁(yè)
文件大?。?/td> 427K
代理商: LTC2488CDE
LTC2488
25
2488f
APPLICATIONS INFORMATION
ness of internal auto calibration circuits begins to degrade.
This results in larger offset errors, full scale errors, and
decreased resolution (see Figures 20 to 27).
Easy Drive ADCs Simplify Measurement of High
Impedance Sensors
Delta-Sigma ADCs, with their high accuracy and high noise
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 LTC2488
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. Figure 28 shows two examples of thermistor
digitization beneting from the Easy Drive technology.
The rst 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 1.6Ω due
to a shift in common mode voltage; far less than the 1%
error of the reference resistors themselves. No amplier
is required, making this an ideal solution in micropower
applications.
Easy Drive also enables very low power, low bandwidth
ampliers to drive the input to the LTC2488. As shown
in Figure 28, CH2 is driven by the LT1494. The LT1494
has excellent DC specs for an amplier 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.
Adding a 1kΩ, 0.1F lter solves this problem by providing
a charge reservoir that supplies the LTC2488 instantaneous
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 1kΩ,
0.1F network errors due to the common mode input
current are cancelled.
相關(guān)PDF資料
PDF描述
LTC2488IDE#TR 4-CH 16-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PQCC14
LTC2488CDE#TR 4-CH 16-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PQCC14
LTC2488IDE 4-CH 16-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PQCC14
LTC2492CDE#TR 4-CH 24-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PDSO14
LTC2492CDE 4-CH 24-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PDSO14
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LTC2488IDE#PBF 功能描述:IC ADC 16BIT DELTA SIG 14-DFN 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(pán) 供應(yīng)商設(shè)備封裝:24-VQFN 裸露焊盤(pán)(4x4) 包裝:Digi-Reel® 輸入數(shù)目和類型:8 個(gè)單端,單極 產(chǎn)品目錄頁(yè)面:892 (CN2011-ZH PDF) 其它名稱:296-25851-6
LTC2488IDE#TRPBF 功能描述:IC ADC 16BIT DELTA SIG 14-DFN 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:2,500 系列:- 位數(shù):16 采樣率(每秒):15 數(shù)據(jù)接口:MICROWIRE?,串行,SPI? 轉(zhuǎn)換器數(shù)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(pán) 供應(yīng)商設(shè)備封裝:38-QFN(5x7) 包裝:帶卷 (TR) 輸入數(shù)目和類型:16 個(gè)單端,雙極;8 個(gè)差分,雙極 配用:DC1011A-C-ND - BOARD DELTA SIGMA ADC LTC2494
LTC2489CDE#PBF 功能描述:IC ADC 16BIT DELTA SIG 14-DFN 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:2,500 系列:- 位數(shù):16 采樣率(每秒):15 數(shù)據(jù)接口:MICROWIRE?,串行,SPI? 轉(zhuǎn)換器數(shù)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(pán) 供應(yīng)商設(shè)備封裝:38-QFN(5x7) 包裝:帶卷 (TR) 輸入數(shù)目和類型:16 個(gè)單端,雙極;8 個(gè)差分,雙極 配用:DC1011A-C-ND - BOARD DELTA SIGMA ADC LTC2494