The Texas Instruments MSP430F6776IPEU is a 16-bit MCU from the MSP430F6xx family, built around the MSP430 CPUXV2 core clocked at 25 MHz. Communication interfaces cover I²C, IrDA, LIN, SPI, and UART/USART, so it can talk to most metrology AFEs, display modules, and host controllers over standard serial buses. The 128-pin LQFP package (20×14 mm body) is a surface-mount part — not socket-friendly for field swaps, but standard for reflow assembly.
25 MHz core and the sigma-delta ADC — what the ratings mean
The 25 MHz CPU clock is enough to run the sigma-delta converter's digital filter and handle the math for energy calculations (active, reactive, apparent) in real time. If you are coming from an 8-bit MCU that struggles to keep up with a 24-bit ADC's data rate, this core gives you the headroom to do the post-processing on-chip without a separate DSP or FPGA. The 7×24-bit sigma-delta ADC is the reason to pick this part. Each channel can sample simultaneously — essential for polyphase metering where you need voltage and current from all phases at the same instant. The 8×10-bit auxiliary ADC handles the less demanding channels (temperature sense, DC offset checks) without tying up the sigma-delta inputs.