Polyphase metering MCU with seven sigma-delta ADCs
The MSP430F6775IPZR: Its defining feature is the integrated array of seven 24-bit sigma-delta analog-to-digital converters, purpose-built for polyphase energy metering — each channel can digitise voltage and current inputs from a resistive divider or current transformer, enabling three-phase plus neutral power calculations with a single chip. The 100-pin LQFP package provides 62 general-purpose I/O lines, enough to drive a segment LCD directly, read pushbuttons, and control relay outputs.
25 MHz core — timing the ADC window
The 25 MHz internal oscillator sets the timing for the sigma-delta ADCs and digital filtering. At 25 MHz, the CPU can execute a multiply-accumulate for the metrology filter in a few dozen cycles, leaving headroom for the communication stack and LCD refresh without dropping samples.
This part is suitable for both production replenishment and new design-ins.