【正文】 X810 專用復位電路，所以 RESET 管教直接接地。12V 外部電源供電，因前置電路需要 177。? 可在線編程, 無需編程器, 可遠程升級；? 內(nèi)部集成 MAX810 專用復位電路，原復位電路可以不用，RESET腳直接短到地。A/D 在轉換結束后向單片機發(fā)送中斷請求，單片機相應響應中斷，通過 16 位并口從 A/D 讀數(shù)。 //將 AD7656 復位 delay1ms(1000)。iK。外接電路簡單，很適合應用于面積有限的印刷電路板。串口連接電路如圖 所示：圖 串口連接電路吉林大學本科畢業(yè)論文（設計）24如圖 13，當外部中斷執(zhí)行 8 次（A/D 采樣兩個周期）后，關外部中斷，這時 CPU 內(nèi)部存儲器中存放有 3 個字符數(shù)組，每個數(shù)組中有 16 個字節(jié)的字符數(shù)據(jù)，CPU 工作在查詢方式下，通過串口將數(shù)據(jù)發(fā)送到計算機。吉林大學本科畢業(yè)論文（設計）26圖 驅動電路輸出信號 信號轉換電路測試將分頻器的 29 倍分頻輸出進行微分得到信號如圖 所示（掃描時間為 10μs，電壓檔位在 2V 檔） 。吉林大學本科畢業(yè)論文（設計）296 對三分量測量的通道差異進行校正的方案設計三分量磁通門地磁場檢測裝置在設計制作中的難點是進行三分量測量時，對各分量進行前置處理的各個通道，其增益不可能完全一致，這會導致測量誤差，影響測量結果的準確性和可靠性。圖 增益可微調(diào)的后級放大吉林大學本科畢業(yè)論文（設計）30利用調(diào)節(jié)放大器增益的方法進行校正，這種方案的特點是：調(diào)試方便，但需要對原來設計的硬件電路做修改。接下來進行三次測量：第一次，用 X 通道測量傳感器 A 輸出，Y 通道測量傳感器 B 輸出，Z 通道測量傳感器 C 輸出，記錄測量數(shù)據(jù) 、}{ax、 ；第二次，用 X 通道測量傳感器 B 輸出，Y 通道測量傳感器}{byczC 輸出， Z 通道測量傳感器 A 輸出，記錄測量數(shù)據(jù) 、 、 ；}{bxcy}{az第三次，用 X 通道測量傳感器 C 輸出，Y 通道測量傳感器 A 輸出，Z 通道測量傳感器 B 輸出，記錄測量數(shù)據(jù) 、 、 。16 位模數(shù)轉換器采用 SAR 型 A/D 轉換器 AD7656，采用+5V 和177。設計給出了計算機數(shù)據(jù)處理的具體方法，測量數(shù)據(jù)可以發(fā)送到計算機進行處理和分析。段老師學術不僅學識淵博，治學嚴謹，而且有著執(zhí)著的敬業(yè)精神和誨人不倦的育人態(tài)度，這些值得我們尊敬，更加值得我們學習。你們在教學和科研中忘我的工作精神感染了我，循循善誘的悉心教導，陪伴我走過了四年的大學生活，同時你們也將吉林大學本科畢業(yè)論文（設計）35是我今后工作中學習的榜樣。此刻，請允許我向多年來教誨和支持我的父母及兄長表達我的感謝，我的成長過程凝聚著你們對我的無私的愛和殷切的期望。5V 輸入電壓范圍可用引腳/軟件選擇高吞吐率：可達到 250kSPS電源 至 可選低功耗：5V 電源下，250kSPS 160mW寬輸入帶寬：50kHz 輸入時，SNR 為 85dB片內(nèi)提供 基準電壓和基準緩沖器吉林大學本科畢業(yè)論文（設計）36支持并行和串行接口高速串行接口兼容 SPI、QSPI 、μWire、DSP待機模式下最大電流 5μA采用 iCOMS 加工工藝64 腳 LQFP 封裝應用：電力線檢測系統(tǒng)儀表和控制系統(tǒng)多軸定位系統(tǒng)簡單描述：AD7656 片內(nèi)集成了 6 通道、16 位、高速、低功耗、逐次逼近型 ADC。三位 CONVST 允許三對 ADC 同時獨立采樣。AD7656 可提供177。若外接基準電壓為 3V，則模數(shù)轉換器的最大允許輸入電壓范圍為177。AGND：模擬接地端，所有模擬輸入信號和外部參考信號電壓都應是對應于該地的電壓。DVCC 和 AVCC 應理想地處于同電位水平，而且電位偏差不超過 。/RD：讀信號，邏輯低電平時使能。DB[1]/SEL B：并行數(shù)據(jù) 1 位/串行選擇 B 路輸出。DB[5]/DCIN A：并行數(shù)據(jù) 5 位/A 路是菊花鏈式。DB[9]/DOUT B：并行數(shù)據(jù) 9 位/串行數(shù)據(jù)輸出 B。DB[14]/REFBUFEN/DIS：并行數(shù)據(jù) 14 位/參考緩沖使能（低電平時）/非使能(高電平時) 。低電平時數(shù)據(jù)以字方式輸出和讀入。10V range and 177。12V input range.Pin Function DescriptionsREFCAPA, REFCAPB,REFCAPC：Decoupling capacitors are connected to these pins to decouple the reference buffer for each ADC pair. Each REFCAP pin should be decoupled to AGND using 10 μF and 100 nF capacitors.V1 – V6：Analog Input16. These are six singleended Analog inputs. The Analog input range on these channels is ddetermined by the RANGE pin.AGND：Analog Ground. Ground reference point for all analog circuitry on the AD7658/AD7657/AD7656. All analog input signals and any external reference signal should be referred to this AGND voltage. All eleven of these AGND pins should be connected to the AGND plane of a system. The AGND and DGND voltages ideally should be at the same potential and must not be more than V apart, even on a transient basis.DVCC：Digital Power. Normally at 5V. The DVCC and AVCC voltages should ideally be at the same potential and must not be more than V apart even on a transient basis. This supply should be decoupled to DGND. 10 μF and 100 nF decoupling capacitors should be placed on the DVCC pin.CONVSTA, B, C：Conversion Start Input A,B,C. Logic Inputs. These inputs are used to initiate conversions on the ADC pairs. CONVSTA is used to initiate 吉林大學本科畢業(yè)論文（設計）41simultaneous conversions on V1 and V2. CONVSTB is used to initiate simultameous conversions on V3 and V4. CONVSTC is used to initiate simultaneous conversions on V5 and V6. When CONVSTX switches from low to high the trackandhold switch on the selected ADC pairs switches from track to hold and the conversion is initiated./CS：Chip Select. Active low logic input. This input frames the data transfer. When both /CS and /RD are logic low in parallel mode the output bus is enabled and the conversion result is output on the Parallel Data Bus lines. When both /CS and WR are logic low in parallel mode DB[15:8] are used to write data to the onchip control register. In serial mode the /CS is used to frame the serial read transfer./RD：Read Data. When both /CS and /RD are logic low in parallel mode the output bus is enabled. In serial Mode the /RD line should be held low.BUSY：BUSY Output. Transitions high when a conversion is started and remains high until the conversion is plete and the conversion data is latched into the Output Data registers.SER/PAR：Serial/parallel selection Input. When low, the parallel port is selected. When high the serial interface mode is selected. In serial mode DB[10:8] take on their SDATA [C:A] function, DB[0:2] take on their DOUT select function, DB[7] takes on its DCEN function. In serial mode DB15 and DB[13:11] should be tied to DGND.DB[0]/SEL A：Data Bit [0]/Select DOUT A. When SER/PAR = 0, this pin acts as a threestate Parallel Digital Output pin. When SER/PAR is =1, this pin takes on its SEL A function, it is used to configure the serial interface. If this pin is 1, the serial interface will operate with one/two/three DOUT ouput pins 吉林大學本科畢業(yè)論文（設計）42and enables DOUT A as a serial output. When operating in serial mode this pin should always be = 1.DB[1]/SEL B：Data Bit [1]/Select DOUT B. When SER/PAR = 0, this pin acts as a threestate Parallel Digital Output pin. When SER/PAR is =1, this pin takes on its SEL B function, it is used to configure the serial interface. If this pin is 1, the serial interface will operate with two/three DOUT ouput pins and enables DOUT B as a serial output. If this pin is 0 the DOUT B is not enabled to operate as a serial Data Output pin and only one DOUT output pin is used.DB[2]/SEL C：Data Bit [2]/Select DOUT C. When SER/PAR = 0, this pin acts as a threestate Parallel Digital Output pin. When SER/PAR is =1, this pin takes on its SEL C function, it is used to configure the serial interface. If this pin is 1, the serial interface will operate with three DOUT ouput pins and enables DOUT C as a serial output. If this pin is 0 the DOUT C is not enabled to operate as a serial Data Output pin.DB[3]/DCIN C：Data Bi