STM32L431CBT6

STM32L431CBT6 is an ultra-low-power Arm Cortex-M4 microcontroller with FPU from STMicroelectronics, running to 80 MHz with 128 KB Flash and 64 KB SRAM in a 48-pin LQFP package, for battery-powered sensing, metering and industrial control. Its selection point is ST FlexPowerControl: 84 µA/MHz run current, 1.0 µA Stop 2 mode with RTC (1.28 µA), 28 nA Standby, 8 nA Shutdown and 4 µs wakeup from Stop, which stretches coin-cell and battery life to years in duty-cycled designs, while the Cortex-M4F still delivers DSP instructions and single-precision floating point for signal conditioning on-chip. The analog set is unusually complete for this class: a 12-bit ADC at 5 Msps (up to 16-bit with hardware oversampling), two 12-bit DAC channels with low-power sample-and-hold, an op-amp with built-in PGA and two ultra-low-power comparators, plus 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, all on a 1.71 V to 3.6 V supply with -40°C to +85°C operation. Selection advice: the CBT6 code is the 128 KB Flash / LQFP-48 / -40°C to +85°C ordering variant — firmware sized above 128 KB or a design needing more than 39 I/Os must move to the 256 KB STM32L431RCT6 in LQFP-64, while a smaller footprint points to the UFQFPN or WLCSP variants of the same die; match the full ordering code character-for-character, since Flash size, package and temperature grade all change with it. This is one of the most counterfeited STM32 order codes in the open market: require lot and date-code traceability.