The STM32F031Kx from STMicroelectronics is a Space Qualified Microcontroller with Clock Rate 32 kHz to 32 MHz, Operating Frequency 48 MHz, Internal RAM Memory SRAM : 4 kB, Flash Memory 16 to 32 kB, Supply Voltage 2 to 3.6 V. Tags: Surface Mount. More details for STM32F031Kx can be seen below.