Texas Instruments MSP430F67781IPEU

Overview

MSP430F67781IPEU from Texas Instruments is a polyphase metering SoC designed for revenue-grade 3-phase electronic watt-hour meters. It integrates a 25-MHz MSP430 CPU with 32-bit multiplier, seven 24-bit sigma-delta ADCs (≤0.1% accuracy over 2000:1 dynamic range), 512KB flash, 16KB RAM, LCD controller (320 segments), and dual power supply management - enabling ANSI C12.20/IEC 62053-compliant energy measurement in utility metering systems.

For engineers reviewing the MSP430F67781IPEU datasheet, MSP430F67781IPEU pinout, MSP430F67781IPEU application, or MSP430F67781IPEU equivalent, key selection criteria include its 7-channel SD24_B ADC architecture, LQFP-128 (PEU) package with 90 GPIOs, RTC with crystal offset calibration, tamper detection support, and ultra-low-power LPM3.5 mode (0.34 µA at 3 V) for backup operation during AC mains failure.

Technical Context

The MSP430F67781IPEU implements a dedicated metering subsystem using seven independent 24-bit sigma-delta modulators with differential inputs and programmable gain, supporting simultaneous phase A/B/C + neutral current/voltage sampling. Its SD24_B module delivers <0.1% error across 40–70 Hz line frequencies using single-point calibration and digital phase correction for CT-based sensing.

Power management includes auxiliary supply switching (AUXVCC1/2/3), core voltage regulation (VCORE), and multiple low-power modes: LPM3 (2.1 µA), LPM3.5 (0.34 µA), and LPM4.5 (0.18 µA). The device executes TI's energy measurement software library natively, computing active/reactive energy, four-quadrant power, and cumulative kWh/kVARh without external co-processing.

Key Specifications

Pinout & Package

128-pin LQFP (PEU) package, 20 mm × 14 mm body size, industrial temperature range (–40°C to +85°C). Pin functions validated per TI SLAS815D Rev. D (2018), Table 4-2 and Figure 4-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MSP430F67781IPEU, the MSP430F67791IPEU adds 16KB RAM for enhanced data buffering but shares identical metering accuracy and peripheral set; the MSP430F67681IPEU reduces SD24_B count to six, targeting cost-sensitive 2-phase implementations while retaining full software compatibility.

Availability

MSP430F67781IPEU is available at Aetrix Electronics and suitable for utility metering, smart grid infrastructure, and industrial energy monitoring requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MSP430F67781IPEU 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 specializing in analog, embedded processing, and connectivity technologies for industrial, automotive, and consumer applications.

The MSP430F677x1 product line is engineered specifically for revenue-grade polyphase energy metering, integrating metrology-grade ADCs, secure real-time clocks, tamper protection, and ultra-low-power operation to minimize system cost and external component count.

FAQ

What is the maximum dynamic range and accuracy of the MSP430F67781IPEU's energy measurement?

The MSP430F67781IPEU achieves <0.1% error over a 2000:1 dynamic range for phase current measurement, verified per ANSI C12.20 and IEC 62053 standards. This performance is enabled by its seven 24-bit sigma-delta ADCs (SD24_B), digital phase correction, and temperature-compensated energy algorithms - all executed on-chip without external calibration components. The MSP430F67781IPEU maintains this accuracy across 40–70 Hz line frequencies using a single calibration point.

Does the MSP430F67781IPEU support tamper detection and secure real-time clock functionality?

Yes, the MSP430F67781IPEU includes hardware-based tamper detection via a dedicated RTC tamper detect pin with Schmitt-trigger input and leakage monitoring, plus a password-protected RTC with crystal offset calibration and temperature compensation. These features meet anti-tamper requirements for revenue meters. The MSP430F67781IPEU also supports secure register locking and backup RAM retention during power loss to preserve tamper events and critical timestamps.

What communication interfaces does the MSP430F67781IPEU provide for AMI/AMR integration?

The MSP430F67781IPEU integrates six enhanced universal serial communication interfaces (eUSCI), configurable as four UARTs, six SPIs, or two I²C ports - enabling concurrent connections to PLC, RF, or optical AMI modules alongside local HMI or sensor interfaces. All eUSCI peripherals support automatic baud-rate detection and deep FIFOs. The MSP430F67781IPEU uses these interfaces to run TI's energy measurement software library and relay calibrated kWh/kVARh data to upstream gateways.

How does the MSP430F67781IPEU manage power during AC mains failure?

The MSP430F67781IPEU supports seamless transition to backup power via three auxiliary supplies (AUXVCC1/2/3), enabling operation in LPM3.5 mode at just 0.34 µA at 3 V - sufficient to maintain RTC, 16KB RAM, and tamper monitoring for >10 years on a coin-cell battery. The MSP430F67781IPEU automatically switches between main and auxiliary rails without firmware intervention, and retains critical metering state during brownouts.

What is the pin count and I/O capability of the MSP430F67781IPEU package?

The MSP430F67781IPEU is housed in a 128-pin LQFP (PEU) package measuring 20 mm × 14 mm, providing 90 general-purpose I/O pins. These include dedicated SD24_B analog inputs (SD0P0–SD6N0), LCD segment/common drivers (COM0–COM7, S0–S39), crystal oscillator pins (XIN/XOUT), RTC capacitor pins (RTCCAP0/1), and auxiliary supply terminals (AUXVCC1–3). All I/Os support configurable drive strength and Schmitt-trigger inputs.