48 MHz Cortex-M0+ in a 5×5 BGA — what fits
The NXP MKL17Z128VMP4R is a Kinetis KL1 series ARM Cortex-M0+ MCU clocked at 48 MHz, with 128 KB Flash and 32 KB RAM. It runs from 1.71 V to 3.6 V and is rated for -40°C to 105°C — the full industrial temperature span. The 64-MAPBGA (5×5 mm) package packs 54 I/O plus I²C, SPI, UART, and LINbus interfaces into a board footprint that fits tight sensor hubs and motor-control modules.
48 MHz — enough for control loops, not for video
The 48 MHz core speed places this MCU in the mid-range of Cortex-M0+ devices — fast enough for sensor fusion, brushless DC motor commutation loops, and Modbus polling, but not intended for heavy DSP or graphics. The 32 KB RAM supports moderate data buffers and stack depth without external memory.