STM32L431RCT6

STM32L431RCT6 is an ultra-low-power Arm Cortex-M4 microcontroller with FPU from STMicroelectronics, running to 80 MHz with 256 KB Flash and 64 KB SRAM in a 64-pin LQFP package, for battery-powered sensing, metering and industrial control where 128 KB Flash is not enough. It shares the STM32L431 family FlexPowerControl efficiency — 84 µA/MHz run current, 1.0 µA Stop 2 mode with RTC, 28 nA Standby, 8 nA Shutdown and 4 µs wakeup from Stop — so the larger memory costs no extra battery budget, and the Cortex-M4F brings DSP instructions and single-precision floating point for on-chip signal conditioning. The peripheral set matches the family full complement: a 12-bit ADC at 5 Msps (up to 16-bit with hardware oversampling, 16 channels on this package), two 12-bit DAC channels with low-power sample-and-hold, an op-amp with built-in PGA, two ultra-low-power comparators, CAN 2.0B Active, four USARTs plus LPUART, three SPIs plus Quad-SPI, three I2C FM+, SAI, SDMMC, SWPMI, RTC with hardware calendar, 14-channel DMA, true random number generator and capacitive-sensing touch channels, with 52 I/Os on a 1.71 V to 3.6 V supply at -40°C to +85°C. Selection advice: the RCT6 code is the 256 KB Flash / LQFP-64 / -40°C to +85°C ordering variant — choose it over the 128 KB STM32L431CBT6 when firmware, logging buffers or protocol stacks exceed 128 KB or when the design needs more than 39 I/Os, and match the full ordering code character-for-character, since Flash size, package and temperature grade all change with it; firmware built for 256 KB will not fit the 128 KB variant. This is one of the most counterfeited STM32 order codes in the open market: require lot and date-code traceability.