The STM32H503EB from STMicroelectronics is a Space Qualified Microcontroller with Clock Rate 32 kHz to 64 MHz, Operating Frequency 250 MHz, Internal RAM Memory SRAM : 2 to 32 kB, Flash Memory 128 kB, Supply Voltage 1.71 to 3.6 V. Tags: Surface Mount. More details for STM32H503EB can be seen below.