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Microchip公司的MCP3911用于16/24位MCU雙路模擬前端(AFE),包含兩個同時取樣的Delta-Sigma ADC,兩個PGA,相位延遲補償區(qū)塊,低漂移基準電壓,調(diào)制輸出區(qū)塊,數(shù)字失調(diào)和增益誤差校正寄存器以及高速20MHz SPI兼容串口.每路有 94.5 dB SINAD, -106.5 dBc THD, 111 dB SFDR,2.7-3.6V工作電壓,可編數(shù)據(jù)速率高達125 ksps,主要用在能量和功率測量,汽車,手持儀表,醫(yī)療和電源監(jiān)視以及音/視頻識別.本文介紹了MCP3911主要特性,方框圖以及用于16位MCU的MCP3911 ADC評估板主要特性, 和PIM MCU連接框圖,電路圖,材料清單和PCB元件布局圖. The MCP3911 is a 2.7V to 3.6V dual channel Analog Front End (AFE) containing two synchronous sampling Delta-Sigma Analog-to-Digital Converters (ADC), two PGAs, phase delay compensation block, low-drift internal voltage reference, modulator output block, digital offset and gain errors calibration registers, and high-speed 20 MHz SPI compatible serial interface. The MCP3911 ADCs are fully configurable with features such as: 16/24-bit resolution, OSR from 32 to 4096, gain from 1x to 32x, independent shutdown and reset, dithering and auto-zeroing. The communication is largely simplified with the one-byte-long commands including various continuous read/write modes that can be accessed by the Direct Memory Access (DMA) of an MCU, and with a separate data ready pin that can be directly connected to an Interrupt Request (IRQ) input of an MCU. The MCP3911 is capable of interfacing a large variety of voltage and current sensors including shunts, current transformers, Rogowski coils and Hall effect sensors. MCP3911主要特性: • Two Synchronous Sampling 16/24-bit Resolution Delta-Sigma A/D Converters • 94.5 dB SINAD, -106.5 dBc Total Harmonic Distortion (THD) (up to 35th harmonic), 111 dB SFDR for Each Channel • 2.7V - 3.6V AVDD, DVDD • Programmable Data Rate up to 125 ksps 4 MHz Maximum Sampling Frequency • Oversampling Ratio up to 4096 • Ultra Low Power Shutdown Mode with <2 μA • -122 dB Crosstalk between the Two Channels • Low Drift 1.2V Internal Voltage Reference: 7 ppm/℃ • Differential Voltage Reference Input Pins • High Gain PGA on Each Channel (up to 32V/V) • Phase Delay Compensation with 1 μs Time Resolution • Separate Modulator Output Pins for Each Channel • Separate Data Ready Pin for Easy Synchronization • Individual 24-bit Digital Offset and Gain Error Correction for Each Channel • High-Speed 20 MHz SPI Interface with Mode 0,0 and 1,1 Compatibility • Continuous Read/Write Modes for Minimum Communication • Low Power Consumption (8.9 mW at 3.3V, 5.6 mW at 3.3V in low-power mode, typical) • Available in Small 20-lead QFN and SSOP Packages, Pin-to-pin Compatible with MCP3901 • Extended Temperature Range: -40℃ to +125℃ MCP3911應(yīng)用: • Energy Metering and Power Measurement • Automotive • Portable Instrumentation • Medical and Power Monitoring • Audio/Voice Recognition 
圖1.MCP3911方框圖 用于16位MCU的MCP3911 ADC評估板 MCP3911 ADC Evaluation Board for 16-Bit MCUs The MCP3911 ADC Evaluation Board for 16-Bit MCUs system provides the opportunity to evaluate the performance of the MCP3911 dual-channel ADC. It also provides a development platform for 16-bit PIC®-based applications, using existing 100-pin PIC microcontroller Plug-in Module (PIM) systems that are compatible with the Explorer 16 and other high pin count PIC®-based demo boards. The system comes with a programmed PIC24FJ256GA110 PIM module that communicates with the Energy Management Utility software for data exchange and ADC setup. MCP3911 ADC評估板亮點: • Dual ADC MCP3911 output display using serial communication to the PC software interface • Simultaneous 55 ksps at OSR32 address loop ALL or 95 dB SINAD at OSR512 performance on MCP3911 • System and ADC performance analysis through graphical PC tools showing noise histogram, frequency domain (FFT), time domain scope plot, and statistical numerical analysis • Robust hardware design with analog grounding and analog/digital separation, allowing low noise evaluation of MCP3911 devices; includes separate power supplies and power planes on a 4-layer board. • PICtail™ Plus connectors for Explorer 16 daughter board compatibility
圖2.MCP3911評估板外形圖
圖3.MCP3911和PIM MCU連接框圖
圖4.MCP3911評估板電路圖:ADC和電源
圖5.MCP3911評估板電路圖:MCU
圖6.MCP3911評估板電路圖  IM模塊
圖7.MCP3911評估板電路圖  CD和UART MCP3911評估板材料清單:
圖8.MCP3911評估板PCB布局圖:頂層
圖9.MCP3911評估板PCB布局圖:底層
圖10.MCP3911評估板元件布局圖:頂層
圖11.MCP3911評估板元件布局圖:底層 詳情請見: 
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