參數(shù)資料
      型號(hào): LTC1287BCJ8
      廠商: LINEAR TECHNOLOGY CORP
      元件分類: ADC
      英文描述: 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, CDIP8
      封裝: 0.300 INCH, HERMETIC SEALED, CERAMIC, DIP-8
      文件頁(yè)數(shù): 4/16頁(yè)
      文件大?。?/td> 315K
      代理商: LTC1287BCJ8
      12
      LTC1287
      1287fa
      U
      S
      A
      O
      PPLICATI
      WU
      U
      I FOR ATIO
      RC Input filtering
      It is possible to filter the inputs with an RC network as
      shown in Figure 11. For large values of CF (e.g., 1F) the
      capacitive input switching currents are averaged into a net
      DC current. A filter should be chosen with a small resistor
      and large capacitor to prevent DC drops across the resistor.
      The magnitude of the DC current is approximately IDC =
      100pF
      × VIN/tCYC and is roughly proportional to VIN. When
      running at the minimum cycle time of 33
      s, the input
      current equals 7.6
      A at VIN = 2.5V. Here a filter resistor of
      8
      will cause 0.1LSB of full-scale error. If a large filter
      resistor must be used, errors can be reduced by increasing
      the cycle time as shown in the Typical Performance
      Characteristics curve Maximum Filter Resistor vs Cycle
      Time.
      Figure 11. RC Input Filtering
      Input Leakage Current
      Input leakage currents also can create errors if the source
      resistance gets too large. For example, the maximum input
      leakage specification of 1
      A (at 85°C) flowing through a
      source resistance of 1k will cause a voltage drop of 1mV
      or 1.6LSB with VREF = 2.5V. This error will be much
      reduced at lower temperatures because leakage drops
      rapidly (see Typical Performance Characteristics curve
      Input Channel Leakage Current vs Temperature).
      SAMPLE-AND-HOLD
      Single-Ended Input
      The LTC1287 provides a built-in sample and hold (S&H)
      function on the +IN input for signals acquired in the single
      ended mode (–IN pin grounded). The sample and hold
      allows the LTC1287 to convert rapidly varying signals (see
      Typical Performance Characteristics curve of S&H
      Acquisition Time vs Source Resistance). The input voltage
      is sampled during the tSMPL time as shown in Figure 8. The
      sampling interval begins at rising edge of CS and continues
      until the falling edge of the CLK before the conversion
      begins. On this falling edge the S&H goes into the hold
      mode and the conversion begins.
      Differential Input
      With a differential input the A/D no longer converts a single
      voltage but converts the difference between two voltages.
      The voltage on the +IN pin is sampled and held and can be
      rapidly time varying. The voltage on the –IN pin must
      remain constant and be free of noise and ripple throughout
      the conversion time. Otherwise the differencing operation
      will not be done accurately. The conversion time is 12 CLK
      cycles. Therefore a change in the –IN input voltage during
      this interval can cause conversion errors. For a sinusoidal
      voltage on the –IN input this error would be:
      Where f(–IN) is the frequency of the –IN input voltage,
      VPEAK is its peak amplitude and fCLK is the frequency of the
      CLK. Usually VERROR will not be significant. For a 60Hz
      signal on the –IN input to generate a 0.25LSB error
      (150
      V) with the converter running at CLK = 500kHz, its
      peak value would have to be 16mV. Rearranging the above
      equation, the maximum sinusoidal signal that can be
      digitized to a given accuracy is given as:
      For 0.25LSB error (150
      V) the maximum input sinusoid
      with a 2.5V peak amplitude that can be digitized is 0.4Hz.
      Reference Input
      The voltage on the reference input of the LTC1287
      determines the voltage span of the A/D converter. The
      reference input has transient capacitive switching cur-
      rents due to the switched capacitor conversion tech-
      nique (see Figure 12). During each bit test of the
      RFILTER
      VIN
      CFILTER
      LTC1287 F11
      LTC1287
      “+”
      “–”
      IDC
      相關(guān)PDF資料
      PDF描述
      LTC1287CCJ8 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, CDIP8
      LTC1287BIJ8 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, CDIP8
      LTC1287CIJ8 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, CDIP8
      LTC1287CIN8 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDIP8
      LTC1287BIN8 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDIP8
      相關(guān)代理商/技術(shù)參數(shù)
      參數(shù)描述
      LTC1287BCN8 功能描述:IC DATA ACQ SYS 12BIT 3V 8-DIP RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - ADCs/DAC - 專用型 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:50 系列:- 類型:數(shù)據(jù)采集系統(tǒng)(DAS) 分辨率(位):16 b 采樣率(每秒):21.94k 數(shù)據(jù)接口:MICROWIRE?,QSPI?,串行,SPI? 電壓電源:模擬和數(shù)字 電源電壓:1.8 V ~ 3.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:40-WFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:40-TQFN-EP(6x6) 包裝:托盤
      LTC1287BCN8#PBF 功能描述:IC DATA ACQ SYS 12BIT 3V 8-DIP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - ADCs/DAC - 專用型 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:50 系列:- 類型:數(shù)據(jù)采集系統(tǒng)(DAS) 分辨率(位):16 b 采樣率(每秒):21.94k 數(shù)據(jù)接口:MICROWIRE?,QSPI?,串行,SPI? 電壓電源:模擬和數(shù)字 電源電壓:1.8 V ~ 3.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:40-WFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:40-TQFN-EP(6x6) 包裝:托盤
      LTC1287CCN8 功能描述:IC DATA ACQ SYS 12BIT 3V 8-DIP RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - ADCs/DAC - 專用型 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:50 系列:- 類型:數(shù)據(jù)采集系統(tǒng)(DAS) 分辨率(位):16 b 采樣率(每秒):21.94k 數(shù)據(jù)接口:MICROWIRE?,QSPI?,串行,SPI? 電壓電源:模擬和數(shù)字 電源電壓:1.8 V ~ 3.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:40-WFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:40-TQFN-EP(6x6) 包裝:托盤
      LTC1287CCN8#PBF 功能描述:IC DATA ACQ SYS 12BIT 3V 8-DIP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - ADCs/DAC - 專用型 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:50 系列:- 類型:數(shù)據(jù)采集系統(tǒng)(DAS) 分辨率(位):16 b 采樣率(每秒):21.94k 數(shù)據(jù)接口:MICROWIRE?,QSPI?,串行,SPI? 電壓電源:模擬和數(shù)字 電源電壓:1.8 V ~ 3.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:40-WFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:40-TQFN-EP(6x6) 包裝:托盤
      LTC1288CN8 功能描述:IC A/D CONV SAMPLING 12BIT 8-DIP 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(gè)單端,單極