100 MHz Cortex-M4 in a WLCSP — what this means for the BOM
The NXP LPC54101J256UK49Z is a 32-bit ARM Cortex-M4 microcontroller running at 100 MHz, with 256 KB of Flash and 104 KB of RAM on a single core. The 49-ball WLCSP (3.29×3.29 mm) saves board area but demands a controlled SMT process.
Memory sizing and peripheral set
256 KB of Flash is enough for a modest application stack — a FreeRTOS kernel, a USB stack, and a sensor-processing pipeline fit without squeezing. The 104 KB RAM gives headroom for double-buffered ADC data or a display frame buffer at QVGA resolution. On the peripheral side, you get 39 GPIOs, a 12-bit ADC with 12 channels, and I²C, SPI, and UART interfaces. There is no CAN or USB on-chip — if your design needs those, you add an external transceiver or bridge, or look at the LPC5411x series with USB. The brown-out detect and POR are built in, so you can skip an external supervisor on the 1.62 V to 3.6 V supply rail.
Temperature grade and deployment environment
Rated from -40°C to 105°C, this MCU is specced for industrial environments. The 105°C upper limit covers self-heating in a sealed enclosure; the -40°C low end handles cold-start in northern installations.