Microchip 双路AFE结和PIC18F65J90 高性能超低耗电表参考设计

发布时间:2012-05-4 阅读量:1190 来源: 我爱方案网 作者:

中心议题:
    *  MCP3901主要特性
解决方案:
    *  MCP3901集合PIC18F65J90的电表参考设计


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.

The communication is largely simplified with various Continuous Read modes that can be accessed by the Direct Memory Access (DMA) of an MCU and with a separate data ready pin that can be connected directly to an Interrupt Request (IRQ) input of an MCU.

The MCP3901 is capable of interfacing to a large variety of voltage and current sensors, including shunts, current transformers, Rogowski coils and Halleffect Sensors.

MCP3901主要特性:


• Two Synchronous Sampling 16/24-bit Resolution Delta-Sigma A/D Converters with Proprietary Multi-Bit Architecture

• 91 dB SINAD, -104 dBc Total Harmonic Distortion (THD) (up to 35th harmonic), 109 dB Spurious-free Dynamic Range (SFDR) for Each Channel

• Programmable Data Rate up to 64 ksps

• Ultra Low-Power Shutdown mode with <2 μA

• -133 dB Crosstalk Between the Two Channels

• Low Drift Internal Voltage Reference: 12 ppm/℃

• Differential Voltage Reference Input Pins

• High Gain PGA on Each Channel (up to 32 V/V)

• Phase Delay Compensation Between the Two Channels with 1 μs time Resolution

• Separate Modulator Outputs for Each Channel

• High-Speed, Addressable 20 MHz SPI Interface with Mode 0,0 and 1,1 Compatibility

• Independent Analog and Digital Power Supplies: 4.5V-5.5V AVDD, 2.7V-5.5V DVDD

• Low-Power Consumption: (14 mW typical at 5V)

• Available in Small 20-lead SSOP and QFN Packages

• Industrial Temperature Ranges:

- Industrial: -40℃ to +85℃

- Extended: -40℃ to +125℃
 


MCP3901应用:


• Energy Metering and Power Measurement

• Automotive

• Portable Instrumentation

• Medical and Power Monitoring


图1.MCP3901方框图

MCP3901和PIC18F65J90电表参考设计

The MCP3901 and PIC18F65J90 Energy Meter Reference Design is a fully functional IEC Class 0.5 compliant single-phase meter. This low-cost design does not use any transformers and requires few external components. The PIC18F65J90 directly drives the LCD, and includes both an isolated USB connection for meter calibration and access to the device power calculations. The system calculates active energy, active power, RMS current, RMS voltage, reactive energy, reactive power, apparent power and other typical power quantities.

The Microchip Energy Meter 1-Phase Software is used to calibrate and monitor the system, and can be used to create custom calibration setups. For some accuracy requirements, only a single point calibration may be needed. The energy meter software offers an automated step-by-step calibration process that can be used to quickly calibrate energy meters.[member]


图2.MCP3901和PIC18F65J90 单相电表外形图
 


图3.电表参考设计数字连接框图

图4.PIC18F65J90计算引擎信号流程图
 


图5.电表参考设计电路图(1)

图6.电表参考设计电路图(2)

图7.电表参考设计电路图(3)
 

电表参考材料清单(BOM):


BILL OF MATERIALS (COMPONENTS NOT INSTALLED)


图8.电表参考PCB元件布局图(顶层)

图9.电表参考PCB元件布局图(底层)
相关资讯
HBM4制程技术竞赛白热化 三星重注1c工艺布局高端存储市场

在全球高端存储芯片产业格局加速重构的背景下,HBM4技术研发已成为DRAM三巨头战略博弈的核心战场。三星电子近期公布的产能扩张计划显示,该公司正通过大规模技术投资构建差异化竞争优势,力图在下一代高带宽存储器领域实现弯道超车。

国产高精度运放崛起:解析RS8531/2如何攻克微弱信号处理难题

随着工业4.0和智能传感技术的快速发展,高精度运算放大器(运放)作为信号链的核心器件,其性能直接影响精密测量系统的可靠性。2025年,润石科技推出的RS8531/2系列超低噪声、零漂移运放,以0.15μVpp的1/f噪声和1.2μV失调电压的突破性参数,展现了国产半导体企业在高端模拟芯片领域的技术实力。该产品不仅对标国际大厂同类器件,更在多个关键技术指标上实现超越,成为精密仪器、医疗设备等领域的优选方案。

苹果折叠屏手机+AR眼镜双线出击:2026产品矩阵首曝光

全球消费电子产业迎来重大技术革新,苹果公司近日被曝出正在加速推进其首款人工智能穿戴设备的研发进程。据彭博社援引知情人士消息称,苹果工程师团队正致力于在2026年底推出代号N401的智能眼镜产品,该设备将集成摄像头阵列、定向麦克风及骨传导扬声器系统,通过深度融合环境感知与AI运算能力重新定义人机交互方式。

汽车智能化催生高可靠性供电需求,豪威推出四通道高边开关芯片

2024年5月23日,豪威集团(OmniVision)宣布推出车规级智能高边开关芯片ONXQ000系列,计划于2025年6月投入量产。该产品针对车载摄像头、超声波雷达等传感器在智能驾驶与数字座舱中的供电痛点,通过四通道集成设计、ASIL-B功能安全认证及创新负压保护技术,为域控制器供电方案提供更高安全性与灵活性。

半导体巨头组织重构引发产业格局猜想:三星代工业务分拆可行性分析

据韩国半导体行业媒体5月22日报道,三星电子半导体部门(DS Division)正面临战略性抉择。继三星生物制剂拆分CDMO业务后,市场对三星晶圆代工业务独立运营的预期显著升温。当前决策的核心矛盾源于客户企业对"设计与制造一体化"模式的信任危机,以及该部门持续亏损的经营现状。