Texas Instruments MSP430F67681IPEU

Overview

MSP430F67681IPEU 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, six 24-bit sigma-delta ADCs, LCD controller (320 segments), and real-time clock with temperature compensation - delivering <0.1% energy measurement accuracy over 2000:1 dynamic range and meeting ANSI C12.20 and IEC 62053 standards in utility metering applications.

For engineers reviewing the MSP430F67681IPEU datasheet, MSP430F67681IPEU pinout, MSP430F67681IPEU application, or MSP430F67681IPEU equivalent, key selection criteria include its 512KB flash/16KB RAM configuration, 128-pin LQFP (PEU) package with 90 GPIOs, ultra-low-power LPM3.5 mode (0.34 µA), and integrated SD24_B ADC architecture optimized for phase current and neutral current sampling in 3-phase 4-wire star topologies.

Technical Context

The MSP430F67681IPEU implements a dedicated metering subsystem with seven independent 24-bit sigma-delta modulators (six active in this variant), supporting simultaneous sampling of voltage and current channels across three phases plus neutral. Its energy calculation engine executes TI's certified energy measurement software library, enabling four-quadrant power computation, digital phase correction for CTs, and temperature-compensated kWh integration without external co-processors.

Power management includes dual auxiliary supplies (AUXVCC1–AUXVCC3), automatic supply switching between main and backup rails, and RTC operation down to 0.34 µA in LPM3.5 - enabling >10-year battery-backed data retention during AC mains failure. The device supports flexible communication via four UART, six SPI, and two I²C interfaces mapped across six eUSCI ports.

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. September 2018, Table 4-1 and Figure 4-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MSP430F67691IPEU, the MSP430F67681IPEU trades 16KB RAM and one SDADC channel for lower cost and identical 512KB flash capacity; compared with MSP430F67671IPEU, it doubles flash for complex DLMS stacks and future firmware updates while retaining identical analog performance and power profile.

Availability

MSP430F67681IPEU is available at Aetrix Electronics and suitable for smart electricity metering, revenue-grade energy monitoring, and AMI endpoint node development requiring stable component supply, long-term lifecycle support, and TI-qualified metrology performance.

Supply support for MSP430F67681IPEU 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, specializing in analog, embedded processing, and connectivity technologies for industrial, automotive, and consumer markets.

The MSP430F676x1 product line was engineered specifically for polyphase revenue metering - integrating metrology-grade ADCs, secure RTC, tamper detection, and ultra-low-power operation to replace multi-chip meter designs with a single SoC solution.

FAQ

What metrology standards does the MSP430F67681IPEU meet?

The MSP430F67681IPEU meets or exceeds ANSI C12.20 Class 0.2 and IEC 62053-22 Class 0.2 accuracy requirements for active energy measurement. Its <0.1% error over 2000:1 dynamic range is validated using TI's certified energy measurement software library and supported by on-chip digital phase correction and temperature compensation features. The MSP430F67681IPEU achieves this compliance without external calibration components.

How many sigma-delta ADC channels does the MSP430F67681IPEU support?

The MSP430F67681IPEU integrates six independent 24-bit SD24_B sigma-delta ADC modules. These are configured to sample up to three phase voltages, three phase currents, and neutral current simultaneously - enabling full 3-phase 4-wire star topology measurement. This matches the SD24_B count specified for the F676x1 family in TI SLAS815D Table 3-1, confirming the MSP430F67681IPEU's six-channel capability.

What is the lowest power consumption mode of the MSP430F67681IPEU?

The MSP430F67681IPEU achieves 0.34 µA in RTC mode (LPM3.5) at 3 V, powering only the real-time clock, backup RAM, and tamper detection circuitry. This mode retains timekeeping and critical data for over 10 years on a standard CR2032 coin cell during AC mains failure. The MSP430F67681IPEU exits LPM3.5 in less than 5 µs, enabling rapid resumption of metrology tasks after power restoration.

Does the MSP430F67681IPEU include an LCD controller?

Yes, the MSP430F67681IPEU includes an integrated LCD controller supporting up to 320 segments with programmable contrast control, static and multiplexed bias modes, and charge-pump voltage generation. It drives COM0–COM7 and SEGx pins directly, eliminating external LCD drivers. The MSP430F67681IPEU maintains full LCD functionality at only 3 µA in LPM3, enabling visible display during extended backup operation.

What communication interfaces are available on the MSP430F67681IPEU?

The MSP430F67681IPEU provides six enhanced USCI (eUSCI) modules: four configurable as UART/IrDA/SPI and two as SPI/I²C. These are mapped across ports P2–P11, supporting concurrent interfaces such as optical port (UART), PLC modem (SPI), and HAN radio (I²C). All eUSCI peripherals operate independently and retain state during LPM3, allowing background communication while metrology runs.