The Texas Instruments MSP430F67771IPEU is a 16-bit microcontroller built around the MSP430 CPUXV2 core, running at 25 MHz.
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.