Texas Instruments MSP430F67781AIPZR

Overview

MSP430F67781AIPZR from Texas Instruments is a polyphase metering SoC designed for high-accuracy 3-phase energy measurement in utility-grade smart meters. It integrates seven 24-bit sigma-delta ADCs (0.1% accuracy over 2000:1 dynamic range), a 25-MHz CPU with 32-bit multiplier, 512KB flash/16KB RAM, LCD controller (320 segments), and dual eUSCI modules supporting UART/I²C/SPI. Its primary role is metrology computation and system control in ANSI C12.20- and IEC 62053-compliant electricity meters.

For engineers reviewing the MSP430F67781AIPZR datasheet, MSP430F67781AIPZR pinout, MSP430F67781AIPZR application, or MSP430F67781AIPZR equivalent, key selection criteria include its 7-channel SD24_B ADC architecture, LQFP-128 package with 90 GPIOs, RTC with tamper detection, ultra-low-power LPM3.5 mode (0.34 µA), and support for shunt/CT/Rogowski sensor inputs in 3-phase 4-wire configurations.

Technical Context

The MSP430F67781AIPZR implements a dedicated metrology subsystem with independent 24-bit sigma-delta modulators per phase channel, enabling simultaneous voltage/current sampling with digital phase correction and temperature-compensated energy calculation. Its SD24_B module supports differential inputs, programmable gain, and 4-quadrant power measurement per phase.

It combines metrology-specific peripherals-including pulse output pins for active/reactive energy calibration, dedicated RTC with crystal offset calibration, and anti-tamper security modules-with general-purpose resources: three-channel DMA, CRC16 engine, four 16-bit timers, and six eUSCI interfaces (four UART/IrDA/SPI + two SPI/I²C) for HAN/PLC/RF communication stacks.

Key Specifications

Pinout & Package

Package: 128-pin LQFP (PEU), 20 mm × 14 mm body size, 0.4 mm pitch, exposed thermal pad not present. Designed for industrial reflow and conformal coating in utility meter environments.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar polyphase metering applications.

Compared with MSP430F67791AIPZR, the MSP430F67781AIPZR trades 16KB RAM for identical metrology precision and flash capacity, while MSP430F67681AIPZR sacrifices one SD24_B channel to reduce analog front-end complexity - both retain the same LQFP-128 package and ultra-low-power RTC operation.

Availability

MSP430F67781AIPZR is available at Aetrix Electronics and suitable for smart electricity meters, revenue-grade energy monitors, grid edge sensor nodes, and tamper-resistant meter modules requiring stable component supply and long-term lifecycle support.

Supply support for MSP430F67781AIPZR 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and consumer markets since 1930.

The MSP430F67781AIPZR belongs to TI's Metrology and Monitoring MCU portfolio, engineered specifically for high-accuracy, low-power energy measurement in utility infrastructure and building automation systems.

FAQ

What is the maximum dynamic range and accuracy of the MSP430F67781AIPZR's metrology ADCs?

The MSP430F67781AIPZR features seven independent 24-bit sigma-delta ADCs achieving <0.1% error over a 2000:1 dynamic range - verified per ANSI C12.20 and IEC 62053 standards. This performance holds across line frequencies from 40 Hz to 70 Hz with single-point calibration, enabling precise measurement from light-load standby to full-rated current in 3-phase meters.

Does the MSP430F67781AIPZR support neutral current measurement in 3-phase 4-wire systems?

Yes, the MSP430F67781AIPZR supports neutral current measurement via its seventh SD24_B channel (SD6P0/SD6N0). Paired with phase A/B/C current inputs, this enables full 3-phase 4-wire metrology including unbalanced load analysis and neutral conductor monitoring - a requirement for ANSI C12.20 Annex A compliance.

How does the MSP430F67781AIPZR handle real-time clock security and tamper detection?

The MSP430F67781AIPZR implements a password-protected RTC with dedicated tamper-detect pins (e.g., RTCCLK, RTCOUT), crystal offset calibration, and temperature compensation. Tamper events trigger non-volatile logging and can force secure erase of sensitive registers - meeting IEC 62056-53 logical security requirements for revenue meters.

What low-power modes are available on the MSP430F67781AIPZR, and what is the current draw in RTC-only operation?

The MSP430F67781AIPZR offers LPM3.5 (RTC active) at 0.34 µA and LPM4.5 (shutdown) at 0.18 µA, both at 3 V. In LPM3.5, the RTC runs from VBAT while retaining RAM contents, enabling >1-year battery-backed timekeeping and energy accumulation during AC mains failure - critical for uninterrupted billing in smart meters.

Can the MSP430F67781AIPZR drive a 320-segment LCD without external components?

Yes, the MSP430F67781AIPZR integrates a full LCD controller supporting up to 320 segments with internal charge pump and programmable contrast. It requires only external COM/SEG traces and a single LCDCAP capacitor - eliminating external bias generators and reducing bill-of-materials cost in sealed meter housings.