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OVERVIEW
AIN0
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AIN8
AIN9
AIN10
AIN11
AIN12
AIN13
AIN14
AIN15
AINCOM
控制
逻辑
VREFPVREFN
AVSS
PLLCAP XTAL1XTAL2
DRDY
PWDN
重置
开始
SPI
接口
CS
SCLK
DIN
DOUT
数字的 过滤
时钟 控制
16−Channel
MUX
AVDD
传感器
偏差
M
UXOUTP
MUX
OUTN
ADCINP 地
AD
CINN
模数转换器 频道 控制
供应 监控
GPIO
G
pio[7:0]
DVDD
温度
Ext Ref 监控
内部的 Ref
模数转换器
CLKSELCLKIO
ADS1258
SBAS297A–JUNE2005–REVISEDSEPTEMBER2005
(vrefp–vrefn).thedigitalfilterreceivesthe
theads1258isaflexible,24-位,低-noiseadc
modulatorsignalandprovidesalow-noisedigital
optimizedforfastmulti-频道,高-决议
输出.theadcchannelblockcontrolsthe
measurementsystems.theconverterprovidesa
multiplexerauto-scanfeature.channelauto-scan
maximumchannelscanrateof23.7ksps,providinga
occursatamaximumrateof23.7ksps.slowerscan
complete16-channelscaninlessthan700µs.
ratescanbeusedwithcorrespondingincreasesin
决议.
Figure33showstheblockdiagramoftheads1258.
Theinputmultiplexerselectstheanaloginputpins
communicationishandledoveranspi-兼容
connectedtothemultiplexeroutputpins
serialinterfacewithasetofsimplecommands
(muxoutp/muxoutn).externalsignalconditioning
providingcontroloftheads1258.onboardregisters
canbeusedbetweenthemultiplexeroutputpinsand
storethevarioussettingsfortheinputmultiplexer,
theadcinputpins(adcinp/adcinn)orthe
sensordetectbias,datarateselection,等.eitheran
multiplexeroutputcanberoutedinternallytotheADC
external32.768khzcrystal,connectedtopinsxtal1
inputswithoutexternalcircuitry.selectablecurrent
andxtal2,oranexternalclockappliedtopinclkio
sourceswithintheinputmultiplexercanbeusedto
canbeusedastheclocksource.whenusingthe
biassensorsordetectforafailedsensor.在-碎片
externalcrystaloscillator,thesystemclockis
systemfunctionreadingsprovidereadbackof
availableasanoutputfordrivingotherdevicesor
温度,supplyvoltage,增益,补偿,andexternal
控制者.一般-purposedigitali/os(gpio)
涉及.theads1258converteriscomprisedofa
provideinputandoutputcontrolofeightpins.
fourth-顺序,delta-sigmamodulatorfollowedbya
programmabledigitalfilter.themodulatormeasures
thedifferentialinputsignalV
在
=(adcinp–adcinn)
againstthedifferentialreferenceinputV
REF
=
figure33.ads1258blockdiagram
12