32 MHz Cortex-M23 in a 4x4 mm QFN
The ATSAML10D15A-MUT is a 32-bit ARM Cortex-M23 microcontroller from Microchip's SAM L10 series, clocked at 32 MHz. It packs 32 KB of flash and 8 KB of SRAM plus 2 KB of dedicated EEPROM — enough for a modest control loop with non-volatile parameter storage, but the 8 KB SRAM means you'll want to keep the RTOS footprint lean or skip dynamic allocation. The 24-VQFN package (4x4 mm) with exposed pad saves board area but requires a well-vented stencil and a controlled hot-air profile if you're reworking it — the pad is the only thermal path, so a poor solder joint under the die can cook the part silently.
Industrial temp and peripheral set
The 1.62 V to 3.63 V supply range lets it run from a single Li-ion cell or a 3.3 V rail without an extra regulator. On the peripheral side, you get I2C, SPI, UART/USART, and LINbus — enough for a CAN-less body controller or a multi-sensor aggregator.
The SAM L10 series is current — no official successor announced.