The STM32WL55Cx STM32WL54Cx from STMicroelectronics is a Space Qualified Microcontroller with Clock Rate 32 kHz to 16 MHz, Operating Frequency 48 MHz, Internal RAM Memory SRAM : 32 kB, Flash Memory 256 KB, Supply Voltage 1.8 to 3.6 V. Tags: Surface Mount. More details for STM32WL55Cx STM32WL54Cx can be seen below.