The STM32L451Rx from STMicroelectronics is a Space Qualified Microcontroller with Clock Rate 32 kHz to 48 MHz, Operating Frequency 80 MHz, Internal RAM Memory SRAM : 160 kB, Flash Memory 256 to 512 kB, Supply Voltage 1.71 to 3.6 V. Tags: Surface Mount. More details for STM32L451Rx can be seen below.