32 MHz Cortex-M0+ for sensor-node edge processing
Peripherals and I/O for compact control
With 28 I/O lines in a 28-UFQFPN (4x4 mm) package, this MCU fits on tight boards where every square millimetre counts. On-chip peripherals include a 10-channel 12-bit ADC, brown-out detect, POR, PWM, and DMA.
For a production build that needs a second-source hedge, the STM32L151CBU6A (Cortex-M3, 32 MHz, 16-channel ADC, USB) is a functional alternative in a different package and temperature grade, not a pin-drop replacement — qualify it separately if dual-sourcing is the goal.