1. Devices
  2. KWxx Series
  3. KW21Z
  4. MKW21Z256xxx4


  • Core

    Cortex-M0+, 48 MHz

  • Family

    KWxx Series

  • Sub-Family


  • CMSIS Pack


The KW21Z is an ultra low-power, highly-integrated single-chip device that enables IEEE® 802.15.4-2011 RF connectivity for portable, extremely low-power embedded systems.
Applications include portable health care devices, access control, security systems, smart energy and home area networks.
The KW21Z Wireless MCU integrates a 2.4 GHz transceiver supporting O-QPSK modulations, an ARM® Cortex®-M0+ CPU, up to 512 KB Flash and up to 128 KB SRAM, 802.15.4 packet processor, hardware security and peripherals optimized to meet the requirements of the target applications.
The KW21Z is an ideal solution for single chip Thread devices including routers and end devices as well as border routers when adding connectivity for communicating with the cloud.




Maximum Clock Frequency 48 MHz
Memory Protection Unit NO_MPU
Floating Point Unit NO_FPU
Trust Zone
Digital Signal Processor
CortexM Vector Extensions
Endian Little-endian