48 MHz Cortex-M0+ with USB in a 3.5 mm BGA
The NXP MKL27Z64VDA4R is a 32-bit ARM Cortex-M0+ microcontroller from the Kinetis KL2 series, clocked at 48 MHz with 64 KB of Flash program memory and 16 KB of RAM. It integrates a full-speed USB 2.0 controller with on-chip transceiver, plus FlexIO for emulating custom serial interfaces like UART, SPI, or I²C beyond the dedicated I²C and SPI peripherals. The 14-channel 16-bit ADC and DMA controller offload the core for sensor-fusion or data-logging loops. This is the part for a compact, USB-connected industrial sensor head, a portable data logger, or a battery-powered IoT node that needs to run moderately complex firmware without stepping up to a Cortex-M4.
36-ball XFBGA — layout and rework reality
The 36-ball XFBGA measures 3.5 x 3.5 mm. The 30 GPIOs support a USB dongle or sensor module with a few external peripherals.