SLAA517F May   2012  – August 2021 MSP430F6720A , MSP430F6720A , MSP430F6721A , MSP430F6721A , MSP430F6723A , MSP430F6723A , MSP430F6724A , MSP430F6724A , MSP430F6725A , MSP430F6725A , MSP430F6726A , MSP430F6726A , MSP430F6730A , MSP430F6730A , MSP430F6731A , MSP430F6731A , MSP430F6733A , MSP430F6733A , MSP430F6734A , MSP430F6734A , MSP430F6735A , MSP430F6735A , MSP430F6736 , MSP430F6736 , MSP430F6736A , MSP430F6736A

 

  1.   Trademarks
  2. 1Introduction
  3. 2System Diagrams
  4. 3Hardware Implementation
    1. 3.1 Power Supply
      1. 3.1.1 Resistor Capacitor (RC) Power Supply
    2. 3.2 Analog Inputs
      1. 3.2.1 Voltage Inputs
      2. 3.2.2 Current Inputs
  5. 4Software Implementation
    1. 4.1 Peripherals Setup
      1. 4.1.1 SD24 Setup
    2. 4.2 Foreground Process
      1. 4.2.1 Formulas
        1. 4.2.1.1 Voltage and Current
        2. 4.2.1.2 Power and Energy
    3. 4.3 Background Process
      1. 4.3.1 Voltage and Current Signals
      2. 4.3.2 Phase Compensation
      3. 4.3.3 Frequency Measurement and Cycle Tracking
      4. 4.3.4 LED Pulse Generation
  6. 5Energy Meter Demo
    1. 5.1 EVM Overview
      1. 5.1.1 Connections to the Test Setup for AC Voltages
      2. 5.1.2 Power Supply Options and Jumper Settings
    2. 5.2 Loading the Example Code
      1. 5.2.1 Opening the Project
  7. 6Results and Calibration
    1. 6.1 Viewing Results
    2. 6.2 Calibrating the Meter
      1. 6.2.1 Gain Correction
      2. 6.2.2 Phase Correction
      3. 6.2.3 Metrology Results
  8. 7References
  9. 8Schematics
  10. 9Revision History

1 Introduction

The MSP430F6736(A) device is the latest metering system-on-chip (SoC), that belongs to the MSP430F67xx family of devices. This family of devices belongs to the powerful 16-bit MSP430F6xxx platform and includes new features and flexibility to support robust 1-phase, 2-phase, and 3-phase metrology solutions. This application report, however, discusses the implementation of a 1-phase solution only. These devices find their application in energy measurement and have the necessary architecture to support them.

The MSP430F6736(A) has a powerful 25-MHz CPU with MSP430CPUX architecture. The analog front end consists of up to three 24-bit ΣΔ analog-to-digital converters (ADC) based on a second-order sigma-delta architecture that supports differential inputs. The sigma-delta ADCs (ΣΔ24) operate independently and can output 24-bit results. They can be grouped together for simultaneous sampling of voltage and currents on the same trigger. In addition, the ADCs have an integrated gain stage that supports gains up to 128 for amplification of low-output sensors. A 32-bit x 32-bit hardware multiplier on this chip can be used to further accelerate math-intensive operations during energy computation. The software supports calculation of various parameters for 1-phase energy measurement. The key parameters calculated during energy measurements are: RMS current and voltage, active and reactive power, active and reactive energy, power factor, and frequency.

The MSP430F6736(A) source code along with the EVM430-F6736 design files that are described in this application report can be downloaded from the One-Phase Metrology with Enhanced ESD Protection Reference Design.