Texas Instruments MSP430F6731AIPZR

Overview

MSP430F6731AIPZR from Texas Instruments is an ultra-low-power mixed-signal microcontroller designed for single-phase electronic watt-hour metering. It integrates three 24-bit sigma-delta ADCs, a 10-bit 200-ksps ADC with temperature sensor, LCD driver supporting up to 320 segments, and four enhanced USCI modules (three UART/IrDA/SPI + one I²C). It operates from 1.8 V to 3.6 V and delivers 265 µA/MHz active current at 8 MHz.

For engineers reviewing the MSP430F6731AIPZR datasheet, MSP430F6731AIPZR pinout, MSP430F6731AIPZR application, or MSP430F6731AIPZR equivalent, key selection criteria include its 32 KB flash / 2 KB RAM configuration, 100-pin LQFP package with dedicated SD24_B analog inputs and auxiliary supply rails (AUXVCC1–3), RTC with crystal offset calibration, and support for metrology-grade energy measurement in utility-grade meters.

Technical Context

The MSP430F6731AIPZR implements a 16-bit RISC CPU with 25-MHz system clock capability, unified clock system featuring FLL, VLO, REFO, and XT1 (32-kHz crystal), and flexible power management including programmable LDO core regulation and multiple low-power modes (LPM3: 1.7 µA, LPM4: 1.6 µA, LPM4.5: 0.78 µA). Its architecture prioritizes precision sensing and long battery life in portable and fixed utility metering applications.

It features three independent 24-bit sigma-delta ADCs with differential PGA inputs for simultaneous voltage/current/neutral channel sampling, a separate 10-bit ADC for auxiliary measurements, hardware multiplier for real-time energy calculations, and three-channel DMA to offload CPU during high-throughput conversions - all synchronized to a common timebase for coherent metrology data capture.

Key Specifications

Pinout & Package

Package: 100-pin LQFP (PZ), 14 mm × 14 mm body size, surface-mount, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar metrology microcontroller applications.

Compared with MSP430F6733AIPZR, the MSP430F6731AIPZR trades flash capacity for lower unit cost while retaining full metrology ADC capability; compared with MSP430F6721AIPZR, it adds the third SD24_B channel essential for IEC 62053-22-compliant neutral current monitoring and leakage detection.

Availability

MSP430F6731AIPZR is available at Aetrix Electronics and suitable for single-phase energy meters, utility grid edge sensors, and smart home energy displays requiring stable component supply, long-term lifecycle support, and metrology-grade accuracy certification.

Supply support for MSP430F6731AIPZR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company delivering analog and embedded processing solutions for industrial, automotive, and consumer applications.

The MSP430F673xA family is engineered specifically for high-accuracy, ultra-low-power electricity metering - integrating metrology-grade ADCs, RTC, LCD, and communication peripherals into a single chip to simplify Class 0.5S meter design.

FAQ

What is the maximum operating frequency of the MSP430F6731AIPZR CPU?

The MSP430F6731AIPZR CPU supports a maximum system clock frequency of 25 MHz, enabled by its integrated FLL and DCO. This allows real-time execution of complex metrology algorithms-including RMS, fundamental power, and harmonic analysis-within tight line-cycle timing windows. The device achieves 265 µA/MHz active current at 8 MHz, confirming efficient performance scaling across its operational range.

Does the MSP430F6731AIPZR support crystal-based real-time clock with temperature compensation?

Yes, the MSP430F6731AIPZR includes a password-protected RTC module with crystal offset calibration and temperature compensation. When paired with a 32.768-kHz tuning-fork crystal on pins XIN/XOUT, it maintains ±2 ppm accuracy from −40°C to +85°C - meeting IEC 62053-21 requirements for time-of-use billing in revenue-grade meters. Calibration data is stored in TLV memory and applied automatically during RTC initialization.

How many analog input channels does the MSP430F6731AIPZR support for metrology-grade measurements?

The MSP430F6731AIPZR supports six external analog input channels for the 10-bit ADC (plus two internal channels including temperature sensor) and three fully independent 24-bit sigma-delta ADCs (SD24_B) with differential PGA inputs. Each SD24_B channel accepts dedicated differential pairs (e.g., SD0P0/SD0N0), enabling simultaneous high-resolution sampling of voltage, current, and neutral current - critical for IEC 62053-22 compliance in single-phase meters.

What LCD configuration options does the MSP430F6731AIPZR provide?

The MSP430F6731AIPZR integrates the LCD_C peripheral supporting static, 2-mux, 3-mux, and 4-mux configurations with up to 320 segments. It provides eight COM outputs (COM0–COM7), programmable contrast control via internal resistor ladder, automatic blinking, and charge-pump voltage generation using the LCDCAP pin. This eliminates external LCD bias ICs and supports common alphanumeric and icon-based displays used in utility meters.

Is the MSP430F6731AIPZR pin-compatible with other devices in the MSP430F673xA family?

Yes, the MSP430F6731AIPZR in the 100-pin LQFP (PZ) package shares identical pinout and electrical characteristics with MSP430F6733AIPZR, MSP430F6734AIPZR, MSP430F6735AIPZR, and MSP430F6736AIPZR. All share the same SD24_B input mapping, AUXVCC rail assignments, COM/LCD pin locations, and JTAG/SBW interface - enabling hardware reuse across meter tiers via flash-only differentiation.