User guide

UG_6631_078 78M6631 Firmware Description Document

Rev 2 5

1 Introduction

This document describes the 78M6631 firmware (6631_3PH_6S_URT_B21), which can be used with the

Teridian™ 78M6631 energy measurement IC. This firmware provides measurements for a 3-phase

system along with simple methods for calibration, configuration, and access to metrology data. This

document contains the following sections:

• Functional Description: Signal Processing Flow, Functions, Calibration, and Operations

• Configuration and Control: Configurability and Settings

• Communications: Communication Interfaces and Protocols Description

The calculations are done on each of the phases individually and the aggregate measurements are also

available as follows:

• Voltage rms (Phase A, B, C)

• Current rms (Phase A, B, C)

• Active Power (Phase A, B, C)

• Apparent Power (Phase A, B, C)

• Reactive Power (Phase A, B, C)

• Power Factor (Phase A, B, C)

• Line Frequency

The firmware also provides measurement results on fundamentals and harmonics. Section 2.2.5

describes how to access and configure harmonics measurements.

The firmware supports Delta and Wye Configurations, the configuration is selectable through a dedicated

pin (D/Y) of the 78M6631 or by modifying the configuration register.

Neutral

LOAD A

LOAD B

LOAD C

IAP

IAN

IBP

IBN

ICP

ICN

V3P3A

Neutral

78M6631

D/Y

Figure 1. Simplified Connection Diagram of a 3-Phase Wye System

Teridian is a trademark of Maxim Integrated Products, Inc.