16 MHz CPU16 core with 512B unified FRAM
The MSP430FR2000IRLLT is a 16-bit MCU from the MSP430 FRAM family, built around the MSP430 CPU16 core clocked at 16 MHz. The headline here is the 512B FRAM program memory — it writes at bus speed without the page-erase penalty of Flash, and it unifies code and data storage so a single memory space serves both. For a sensor node or control loop that logs calibration constants or runtime counters, FRAM eliminates the EEPROM emulation layer and the wear-leveling logic that Flash demands. The 512 x 8 RAM is modest — enough for a super-loop scheduler or a small state machine, but a full RTOS with multiple stacks will exhaust it before the code space does. The 12 I/O count means each pin needs a clear assignment early in the schematic; there is no room for unused pins to float.
Package and board-fit: 24-VFQFN with exposed pad
A 3.3 V rail is the obvious choice, but the low end lets the part run from a 2xAA battery stack down to near-depletion without a boost converter.
Peripherals and connectivity for sensor-node designs
The PWM output is useful for driving a LED indicator or a small piezo buzzer directly. Serial connectivity covers IrDA, SCI, SPI, and UART/USART. The SPI and UART are the workhorses for external sensors (temperature, humidity, pressure) and short-range radios. The IrDA module is present but rarely used in new designs — it adds no pin cost since it shares the UART pins.
Active production and compliance posture
ROHS3 compliance is confirmed, covering all six original substances plus the four phthalates, with no exemption-based carve-outs.