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| MCP3919三路ADC模擬前端(AFE)解決方案 |
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| 文章來源： 更新時間：2014/11/17 15:35:00 |
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Microchip公司的MCP3919是三路模擬前端(AFE),包括三路同步取樣Delta-Sigma模數(shù)轉(zhuǎn)換器(ADC),三路PGA,相位延遲補(bǔ)償區(qū)塊,低漂移基準(zhǔn)電壓,數(shù)字失調(diào)和增益誤差效準(zhǔn)寄存器以及高速20MHz SPI兼容串口.ADC具有16/24位分辨率,32-4096過取樣比率(OSR),增益1x-32x,單獨關(guān)斷和重起,抖動和自動調(diào)零.主要用在多相電表,能量測量,汽車電子,手持儀表,音頻/視頻識別以及醫(yī)療和電源監(jiān)測.本文介紹MCP3919主要特性,框圖和應(yīng)用電路,以及用于16位MCU的MCP3919 ADC評估板特性亮點,電路圖,材料清單和PCB設(shè)計圖.
The MCP3919 is a 3V three-channel Analog Front End (AFE) containing three synchronous sampling delta-sigma Analog-to-Digital Converters (ADC), three PGAs, phase delay compensation block, low-drift internal voltage reference, digital offset and gain error calibration registers and high-speed 20 MHz SPI-compatible serial interface.
The MCP3919 ADCs are fully configurable with features such as: -32x16/24-bit resolution, Oversampling Ratio (OSR) from 32 to 4096, gain from 1x to 32x, independent Shutdown and Reset, dithering and autozeroing.
The communication is largely simplified with 8-bit commands including various continuous read/write modes and 16/24/32-bit data formats that can be accessed by the Direct Memory Access (DMA) of an 8/16- or 32-bit MCU and with the separate data ready pin that can directly be connected to an Interrupt Request (IRQ) input of an MCU.
The MCP3919 includes advanced security features to secure the communications and the configuration settings such as a CRC-16 checksum on both serial data outputs and static register map configuration. It also includes a register-map lock through an 8-bit secure key to stop unwanted write commands from processing.
The MCP3919 is capable of interfacing with a variety of voltage and current sensors, including shunts, current transformers, Rogowski coils and Hall-effect sensors.
MCP3919主要特性:
• Three Synchronous Sampling 24-bit Resolution Delta-Sigma A/D Converters
• 93.5 dB SINAD, -107 dBc Total Harmonic Distortion (THD) (up to 35th Harmonic), 112 dBFS SFDR for Each Channel
• Enables 0.1% Typical Active Power Measurement Error over a 10,000:1 Dynamic Range
• Advanced Security Features:
- 16-bit Cyclic Redundancy Check (CRC) Checksum on All Communications for Secure Data Transfers
- 16-bit CRC Checksum and Interrupt Alert for Register Map Configuration
- Register Map Lock with 8-bit Secure Key
• 2.7V-3.6V AVDD, DVDD
• Programmable Data Rate up to 125 ksps:
- 4 MHz Maximum Sampling Frequency
- 16 MHz Maximum Master Clock
• Oversampling Ratio up to 4096
• Ultra-Low Power Shutdown Mode with < 10 μA
• -122 dB Crosstalk between Channels
• Low Drift 1.2V Internal Voltage Reference: 9 ppm/°C
• Differential Voltage Reference Input Pins
• High Gain PGA on Each Channel (up to 32 V/V)
• Phase Delay Compensation with 1 μs Time Resolution
• 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 Time with Dedicated 16/32-bit Modes
• Available in a 28-lead 5 x 5 mm QFN and 28-lead SSOP Packages
• Extended Temperature Range: -40°C to +125°C
MCP3919應(yīng)用:
• Polyphase Energy Meters
• Energy Metering and Power Measurement
• Automotive
• Portable Instrumentation
• Medical and Power Monitoring
• Audio/Voice Recognition
圖1. MCP3919框圖
圖2. MCP3919應(yīng)用案例電路圖
MCP3919 ADC評估板
The MCP3919 ADC Evaluation Board for 16-Bit MCUs system provides the opportunity to evaluate the performance of the MCP3919 three-channel Analog Front End (AFE).
It also provides a development platform for 16-bit microcontroller-based applications, using the existing 100-pin PIC® microcontroller Plug-in Module (PIM) systems that are compatible with the Explorer 16 Evaluation Board (DM240001) and other high pin count PIC device 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.
The MCP3919 ADC Evaluation Board for 16-Bit MCUs uses the Energy Management Utility software for evaluation of the MCP3919 via a USB connection to the board. A download link for this software can be found on the evaluation board’s web page. For instructions on the use of this software, refer to the supporting documentation included within the application install package.
用于16位MCU的MCP3919 ADC評估板特性亮點:
• Three-channel ADC MCP3919 output display using serial communication to the
PC software interface.
• Simultaneous 57 ksps at OSR32 address loop ALL or 95 dB SINAD at OSR512
performance on MCP3919.
• 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 the MCP3919 device; includes separate power supplies and power planes on a four-layer board.
• PICtail™ Plus connectors for Explorer 16 daughter board compatibility.
圖3. MCP3919 ADC評估板外形圖
16位MCU MCP3919 ADC評估板包括:
• MCP3919 ADC Evaluation Board for 16-Bit MCUs (Part number ADM00573)
• PIC24FJ256GA110 PIM
• USB Cable
• Important Information Sheet
圖4. PIM/MCP3919 ADC數(shù)字連接框圖
圖5. MCP3919 ADC評估板電路圖(1):電源電路
圖6. MCP3919 ADC評估板電路圖(2):ADC電路
圖7. MCP3919 ADC評估板電路圖(3):MCU電路
圖8. MCP3919 ADC評估板電路圖(4):PIM模塊電路
圖9. MCP3919 ADC評估板PCB設(shè)計圖:頂層
圖10. MCP3919 ADC評估板PCB設(shè)計圖:底層
MCP3919 ADC評估板材料清單(BOM):
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