120 MHz Cortex-M4 — what it means for the control loop
The MK22FN128CAH12R runs a single ARM Cortex-M4 at 120 MHz with a single-cycle multiply and hardware divide, plus a floating-point unit for real-time math. That clock rate puts it at the upper end of the Kinetis K20 value line — enough headroom for a sensor fusion loop or a USB audio stream without thrashing the scheduler. The 128 KB Flash and 24 KB RAM fit a moderate firmware image with a USB stack and a couple of PID loops; if your BOM needs more buffer for graphics or data logging, the pin-compatible higher-density siblings in the K20 family share the same footprint.
Peripherals and connectivity
On-chip peripherals include DMA, I²S, LVD, POR, PWM, and WDT. Connectivity covers I²C, IrDA, SPI, UART/USART, USB, and USB OTG — the USB OTG controller is the standout, letting this MCU act as host or device for direct flash-drive logging or keyboard input without an external PHY. Two 16-bit ADCs and one 12-bit DAC handle analog front-end tasks. The 40 GPIOs are enough for a keypad-plus-display interface or a modest sensor array.