Microchip MCP3901和PIC18F65J90 电表参考设计
Microchip公司的MCP3901是两路模拟前端(AFE),集成了两个同步取样16位/24位Delta-Sigma ADC,两个PGA,相位延迟补偿的内部基准电压,调制器输出区块,以及高速成速0MHz SPI兼容的串行接口.每路具 91 dB SINAD, -104 dBc THD,109dB SFDR,可编数据速率高达64ksps.主要用在电表和能量管理,汽车,手提仪表,医疗和电源监视.本文介绍了MCP3901主要特性,方框图以及采用MCP3901和PIC18F65J90电表参考设计的数字连接框图,PIC18F65J90计算引擎信号流程图,参考设计电路图,材料清单和PCB元件布局图.
The MCP3901 is a dual channel Analog Front End (AFE) containing two synchronous sampling Delta-Sigma Analog-to-Digital Converters (ADC), two PGAs, phase delay compensation block internal voltage reference, modulator output block, and high-speed 20 MHz SPI compatible serial interface. The converters contain a proprietary dithering algorithm for reduced Idle tones and improved THD.
The internal register map contains 24-bit wide ADC data words, a modulator output byte, as well as six writable control registers to program gain, oversampling ratio, phase, resolution, dithering, shutdown, Reset and several communication features.
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