Core compute and memory budget
The STM32L051T8Y6TR runs an ARM Cortex-M0+ core at 32 MHz — the throughput ceiling is set by the flash wait-state profile, not the core clock. For a sensor node polling an ADC and logging to EEPROM, the 64 KB flash (64K x 8) leaves room for a modest application stack after the HAL and RTOS footprint. On-chip RAM is 8K x 8, with a separate 2K x 8 EEPROM array. The EEPROM is useful for calibration constants or fault logs that need single-byte erase/write without wear-leveling — the flash sectors are better suited for firmware images.
Package and board-fit
The 29 I/O lines break out through the WLCSP bumps; a 4-layer PCB with microvias is typical for fan-out.
Peripheral set and connectivity
Connectivity covers I²C, IrDA, SPI, and UART/USART — enough for a sensor hub talking to an external ADC over SPI and logging to an SD card over UART.
RoHS3 compliant, which covers the EU RoHS directive 2015/863. The base product number STM32L051 is the designator for the whole family; the T8Y6 suffix specifies the 64 KB flash, 36-WLCSP package, and tape-and-reel delivery.