Rainbow-electronics ADC08832 Uživatelský manuál Strana 1

ADC08831/ADC088328-Bit Serial I/O CMOS A/D Converters with Multiplexerand Sample/Hold FunctionGeneral DescriptionThe ADC08831/ADC08832 are 8-bit succe

Timing Diagrams (Continued)ADC08831 Start Conversion TimingDS100108-24ADC08831 TimingDS100108-25*LSB first output not available on ADC08831.ADC08832 T

ADC08832 Functional Block DiagramDS100108-12*Some of these functions/pins are not available with other options.www.national.com11

Functional Description1.0 MULTIPLEXER ADDRESSINGThe design of these converters utilizes a comparator struc-ture with built-in sample-and-hold which pr

Functional Description (Continued)3.0 Reducing Power ConsumptionThe ADC08831 operate up to a 2MHz clock frequency, orabout 181 ksps. At 5V supply, it

Functional Description (Continued)5.0 THE ANALOG INPUTSThe most important feature of these converters is that theycan be located right at the analog s

Functional Description (Continued)The VREFIN (or VCC) voltage is then adjusted to provide acode change from FEHEXto FFHEX. This completes the ad-justm

ApplicationsLow-Cost Remote Temperature SensorDS100108-6Operating with Ratiometric TransducersDS100108-7*VIN(−)=0.15 VCC15%of VCC≤ VXDR≤ 85%of VCCwww.

Applications (Continued)Span Adjust; 0V ≤ VIN≤ 3VDS100108-8Zero-Shift and Span Adjust: 2V≤VIN≤ 5Vwww.national.com17

Applications (Continued)Protecting the InputDS100108-9Diodes are 1N914Digital Load CellDS100108-10•Uses one more wire than load cell itself•Two mini-D

Applications (Continued)4 mA-20 mA Current Loop ConverterDS100108-11•All power supplied by loop•1500V isolation at outputIsolated Data ConverterDS1001

Connection DiagramsOrdering InformationTemperature Range PackageIndustrial (−40˚C ≤ TJ≤ +85˚C)ADC08831INN08EADC08832INADC08831IWM,M14BADC08832IWM,ADC0

Applications (Continued)A “Stand-Alone” Hook-Up for ADC08832 EvaluationDS100108-39www.national.com 20

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Physical Dimensions inches (millimeters) unless otherwise notedOrder Number ADC08831IWM, ADC08832IWM,NS Package Number M14BOrder Number ADC08831IM or

Physical Dimensions inches (millimeters) unless otherwise noted (Continued)Order Number ADC08831IN, ADC08832INNS Package Number N08Ewww.national.com23

Physical Dimensions inches (millimeters) unless otherwise noted (Continued)LIFE SUPPORT POLICYNATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITIC

Absolute Maximum Ratings (Notes 1, 3)If Military/Aerospace specified devices are required,please contact the National Semiconductor Sales Office/Distr

Electrical Characteristics (Continued)The following specifications apply for VCC=VREF=+5VDC, and fCLK=2 MHz unless otherwise specified. Boldface limit

Dynamic CharacteristicsThe following specifications apply for VCC=5V, fCLK=2MHz, TA=25˚C, RSOURCE=50Ω,fIN=45kHz, VIN=5VP-P,VREF=5V, non-coherent 2048

Block DiagramDS100108-47*For ADC08831 VREFpin is available, for ADC08832 DI pin is available, and VREFis tied to VCCPin names in parentheses refer to

Typical Performance Characteristics The following specifications apply for TA=25˚C, VCC=VREF=5V, unless otherwise specified.Linearity Error (TUE) vsRe

Typical Performance Characteristics The following specifications apply for TA=25˚C, VCC=VREF=5V, unless otherwise specified. (Continued)Leakage Curren

TRI-STATE Test Circuits and WaveformsTiming DiagramsDS100108-20DS100108-21Data Input TimingDS100108-22Data Output TimingDS100108-23www.national.com9