The STM32F303Kx from STMicroelectronics is a Space Qualified Microcontroller with Clock Rate 32 kHz to 32 MHz, Operating Frequency 72 MHz, Internal RAM Memory SRAM : 12 kB, Flash Memory 32 to 64 KB, Supply Voltage 2.4 to 3.6 V. Tags: Surface Mount. More details for STM32F303Kx can be seen below.