《电子技术应用》

Maxim78M6618PDU1低成本功率分配解决方案

作者:Maxim公司
2011/12/15 0:00:00

Maxim公司的78M6618是高度集成的独立监测八路单相AC出口能量的IC,集成了多个主机接口,LCD驱动器和可配置的I/O口.78M6618提供用于和电压与电流传感器接口的十个模拟输入端,并具有21位delta-sigma ADC,独立的32位计算引擎(CE),数字温度补偿以及精密的电压基准源,能在2000:1动态范围内提供优于0.5%的精度,非常适合用在嵌入式高精度AC功率和能量的测量.本文介绍了78M6618主要特性,方框图,以及78M6618低成本功率分配单元(PDU)评估板主要特性,电路图和材料清单与78M6618 PDU-CT 评估板电路图与材料清单:

The Teridian 78M6618 is a highly integrated IC for independent monitoring and measurement of up to eight single-phase AC outlets. With multiple host interface options, an integrated LCD driver, and configurable I/Os, the device is ideal for metered power distribution units (PDUs) and rack enclosures for the data center, as well as intelligent power strips and subpanels in the grid-friendly digital home. At the measurement interface, the device provides 10 analog inputs for interfacing to voltage and current sensors. Scaled voltages from the sensors are fed to our Single Converter Technology® that uses a 21-bit delta-sigma ADC, independent 32-bit compute engine (CE), digital temperature compensation, and precision voltage references to provide better than 0.5% accuracy over a wide 2000:1 dynamic range. The integrated MPU core and 128KB of flash memory provides a flexible means of configuration, postprocessing, data formatting, interfacing to host processor through a UART or SPI™ interface, displaying output data to an LCD, or using DIO pins for intelligent relay control. Complete firmware for common applications is available from Teridian and can be loaded into the IC during manufacturing test. Alternatively, a complete array of ICE, development tools, and programming libraries are available to allow customization MPU code for each application.

78M6618主要特性:

< 0.5% Wh Accuracy Over Wide 2000:1 Current Range and Over Temperature

Exceeds IEC 62053/ANSI C12.20 Standards 

Voltage Reference < 40ppm/℃ 

10 Sensor Inputs—V3P3 Referenced 

21-Bit Delta-Sigma ADC with Independent 32-Bit Compute Engine (CE) 

8-Bit MPU (80515), One Clock Cycle per Instruction with 4KB MPU XRAM 

128KB Flash with Security 

Integrated ICE for MPU Debug 

32kHz Time Base with Hardware Watchdog Timer 

UART and High-Speed Slave SPI Host Interface Options 

Up to 19 General-Purpose 5V Tolerant I/O Pins 

LCD Driver (Up to 70 Pixels) 

Packaged in a Lead(Pb)-Free/RoHS-Compliant (6/6) 68-Pin QFN 

Robust Sub-Metering Application Firmware:

o True RMS Calculations for Current, Voltage, Line Frequency, Real Power, Reactive Power, Apparent Power, and Power Factor

o Accumulated Watt-Hours, Kilowatt-Hours, and Cost

o Intelligent Switch Control at Zero Crossings

o Digital Temperature Compensation

o Phase Compensation (+/-15degree)

o Quick Calibration Routines

o 46-64Hz Line Frequency Range with Same Calibration

o Programmable Alarm Thresholds

o High-Level UART Communication Protocols

o High-Level SPI Communication Protocols

图1.78M6618功能方框图

图2.78M6618 AFE方框图

78M6618低成本功率分配单元(PDU)评估板

The Teridian™ 78M6618 PDU1 evaluation board is an example of a low-cost power distribution unit (PDU) utilizing the 78M6618 system-on-chip (SoC). The 78M6618 monitors the AC line voltage and eight load currents, and controls switching of eight internal load relays. The embedded firmware calculates the RMS line voltage and RMS load currents, watts, VAs, VARs, and power factor. The real-time data is transmitted to a PC via a USB interface for display in a Windows®-based graphical user interface (GUI). The 78M6618 UART interface is used as the communications link to an on-board isolated USB interface IC.

Included with the 78M6618 PDU1 is a Windows-based GUI for simplified access to the following measurement data and controls:

• RMS voltage and current

• Real, apparent, and reactive power and power factor

• Accumulated energy usage and expense tracking

• Line frequency

• Minimum and peak parameter tracking

• Alarm indicators

• Programmable alarm thresholds

• Internal load relay (16A) control

图3.78M6618 PDU1评估板外形图

78M6618 PDU1评估板包括:

The 78M6618 PDU1 evaluation kit includes:

• 78M6618 PDU1_DIFF evaluation board

• Universal AC to 12 V DC power supply with international plug adapters

• ICE Adaptor board

• USB A/B cable

图4.78M6618 PDU1评估板电路图(1)

图5.78M6618 PDU1评估板电路图(2)

图6.78M6618 PDU1评估板电路图(3)

图7.78M6618 PDU1评估板电路图(4)
78M6618 PDU1评估板材料清单:





图8.78M6618 PDU1评估板PCB布局图:上图,顶层;下图,底层

图9.78M6618 PDU-CT 评估板外形图

图10.78M6618 PDU-CT 评估板电路图(1)

图11.78M6618 PDU-CT 评估板电路图(2)

图12.78M6618 PDU-CT 评估板电路图(3)

图13.78M6618 PDU-CT 评估板电路图(4)
78M6618 PDU-CT 评估板材料清单:




图14.78M6618 PDU-CT 评估板PCB布局图:上图,顶层;下图,底层
详情请见:
http://datasheets.maxim-ic.com/en/ds/78M6618.pdf

http://pdfserv.maxim-ic.com/en/an/UG5220.pdf



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