The Texas Instruments MSP430F67771IPEU is a 16-bit microcontroller built around the MSP430 CPUXV2 core, running at 25 MHz. It packs 256 KB of Flash program memory and 32 KB of RAM, and its standout feature is the set of seven 24-bit sigma-delta ADCs — purpose-designed for polyphase energy metering and high-accuracy measurement applications. The 128-LQFP package gives access to 90 I/O lines, with connectivity spanning I²C, SPI, UART/USART, IrDA, and LINbus.
25 MHz core — what it means for the metering loop
At 25 MHz, the CPUXV2 has enough headroom to run the sigma-delta filter calculations and the energy computation firmware in real time while still servicing the LCD controller and communications stack. For a typical three-phase meter reading voltage and current on all phases simultaneously, this clock rate avoids the need for a dedicated DSP coprocessor.
Seven 24-bit sigma-delta ADCs — built for polyphase metering
The seven 24-bit sigma-delta converters are the reason this part exists. They map directly to three voltage and three current channels for a three-phase system, plus a neutral current channel — no external multiplexer or multiple ADC scans needed. The separate 8×10-bit ADC handles auxiliary inputs like temperature or tamper detection without loading the metering path.