78M6631 Ver la hoja de datos (PDF) - Maxim Integrated

Número de pieza

componentes Descripción

Fabricante

78M6631

3-Phase Power Measurement IC

Maxim Integrated 

78M6631 Data Sheet

DS_6631_056

1.4 Analog Front-End (AFE)

The AFE functions as a data acquisition system, controlled by the MPU. The main blocks in the AFE

consist of an input multiplexer, a delta-sigma A/D converter, a FIR decimation filter and a voltage

reference. The metrology input signals (IAP, IAN, IBP, IBN, ICP, ICN, VA, VB, VC, and TEMP) are

multiplexed before being sampled by the ADC. The ADC output is decimated by the FIR filter and the

results are stored in RAM where they can be accessed by the CE and the MPU.

The functionality of the AFE is established for various system requirements with different CE code. AFE

programmability includes, but is not limited to:

• Input multiplexer settings

• Voltage supply and temperature monitor inputs

• ADC sampling rate

• FIR length/resolution

IAP

IAN

+-

IBP

IBN

+-

ICP

ICN

+-

MUX

VA

VB

VC

VREF

VBIAS

VBIAS

∆Σ ADC

CONVERTER

V3P3A

-

V3P3D

+

FIR

TEMP

MUX

MUX

CTRL

VREF

CROSS

CK32

VREF

FIR_DONE

FIR_START

4.9152 MHz

Figure 2: AFE Block Diagram

1.4.1 Analog Current and Voltage Inputs

With all CE code implementations for the 78M6631, pins IAP, IAN, IBP, IBN, ICP, ICN, VA, VB, and VC

are analog inputs to the AFE for measuring current and voltage. Various current sensor technologies can

be supported including Current Transformers, Resistive Shunts, and Rogowski coils.

8

Rev 1

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