24-bit sigma-delta ADC on a 16-bit MCU — the metering-specific MSP430
Its defining feature is an integrated 24-bit sigma-delta analog-to-digital converter — a single channel that resolves microvolt-level signals from current transformers or shunt resistors in energy-metering and precision-sensing applications.
12 MHz core — enough for a metering loop, not for a control stack
The 12 MHz clock is modest by MCU standards, but it is deliberately paired with the 24-bit ADC and the MSP430's single-cycle multiplier to sustain a continuous metering algorithm (voltage/current samples, power calculation) without dropping samples. The Flash program memory is 8 KB — that is tight: the ADC driver, calibration constants, and a basic Modbus or UART framing will fit, but a full RTOS or USB stack will not. The 512 x 8 RAM (512 bytes) is similarly lean; expect to use register-based variables and a small stack. Brown-out detect and a watchdog timer are on-chip.
The MSP430AFE231IPW comes in a 24-pin TSSOP package (4.40 mm width, 0.65 mm pitch), surface-mount only. With 11 general-purpose I/O lines, the pin count is limited — plan on sharing the SPI/UART peripheral for both configuration and data output.