80 MHz Cortex-M4 in a WLCSP-36 — what that means for your board
The STMicroelectronics STM32L412TBY6TR is a 32-bit ARM Cortex-M4 MCU from the STM32L4 ultra-low-power series, clocked at 80 MHz with 128 KB Flash and 40 KB SRAM. It is built for battery-operated and power-sensitive applications — think portable medical devices, sensor nodes, and field instruments — where the 1.71 V to 3.6 V supply range lets it run directly from a single Li-ion cell down to near-empty without a boost regulator. The 36-ball WLCSP (2.58 x 3.07 mm) saves significant board area compared to a QFN, but requires a controlled SMT process and underfill if the board sees vibration or thermal cycling.
Memory and peripherals — fitting the firmware and the bus
Temperature grade and environment
Rated for -40°C to 85°C ambient, this part suits industrial control cabinets, outdoor telecom pedestals, and automotive cabin-adjacent modules (not under-hood). The WLCSP package's solder-joint reliability at temperature extremes depends on the PCB's coefficient of thermal expansion — a board with a matched CTE or a small die-to-board ratio is recommended for repeated -40°C cycles.
Lifecycle and sourcing
The STM32L412TBY6TR carries an active lifecycle status from ST. No end-of-life notice or last-time-buy window is in effect. For current pricing and availability, submit an RFQ — the part is sourced through independent distribution and quoted to order.