STM32C551KCU6

STM32C551KCU6 is a mainstream 32-bit microcontroller from STMicroelectronics in a UFQFPN-32 package, sharing its die with the larger STM32C551 versions: an Arm Cortex-M33 core with FPU and DSP instructions at 144 MHz, 512 KB of dual-bank Flash, 128 KB of SRAM, an I3C port and USB 2.0 full-speed on a 2.7 to 3.6 V supply. The small package is the selection point: it puts the full C5 memory map and core performance into the family's smallest pin count, for compact or height-constrained boards - sensor hubs, wearables and space-limited control nodes - where a leaded package will not fit. The trade is I/O count, since a 32-pin footprint physically exposes fewer pins than the 48-pin and 100-pin codes of the same die. Selection advice: choose the KCU6 when board area is the binding constraint and the reduced I/O set still covers the design; if hand soldering or optical inspection matters, take a leaded LQFP code instead. FDCAN is only on the STM32C552, not this 551. ST announced the series entering production in March 2026 and the eStore lists this exact code as Active. Parameters verified against STMicroelectronics documentation.