Kinetis® KW31Z-2.4 GHz Bluetooth Low Energy Wireless Radio Microcontroller (MCU) based on Arm® Cortex®-M0+ Core

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Block Diagram

Kinetis® W Series KW31Z MCUs Block Diagram

Kinetis<sup>&#174;</sup> W Series KW31Z MCUs Block Diagram


Bluetooth Low Energy Radio Features

  • 2.4 GHz Bluetooth Low Energy version 4.2 Compliant
  • Typical Receiver Sensitivity (Bluetooth Low Energy) = -95 dBm
  • Programmable Transmitter Output Power up to +3.5 dBm

Core and Memories

  • Up to 48 MHz Arm® Cortex®-M0+ core
  • Up to 512 KB Flash memory
  • Up to 128 KB SRAM
  • Excellent coexistence performance
  • Integrated balun to reduce system cost and PCB board area

Low Power Consumption and Operating Voltage Ranges

  • Nine low-power modes to provide power optimization based on application requirements
  • Typical Rx/Tx Current (DC/DC Enabled): 6.5 mA / 8.4 mA
  • Bypass Voltage: 1.71V to 3.6V
  • DCDC Converter Buck Configuration: 2.1V to 4.2V
  • DCDC Converter Boost Configuration: 0.9V to 1.795V

Analog modules

  • 16-bit Analog-to-Digital Converter (ADC)
  • 12-bit Digital-to-Analog Converter (DAC)
  • 6-bit High Speed Analog Comparator (CMP)


  • AES-128 Accelerator (AESA), True Random Number Generator (TRNG)

Supported Software

  • Bluetooth Low Energy Host Stack and Profiles
  • Generic FSK Link Layer Software
  • Kinetis® Software Development Kit (SDK)
  • FreeRTOS kernel and a bare-metal non-preemptive task scheduler
  • Support for MCUXpresso and IAR

Comparison Table

Kinetis KW41Z Family Solutions

Part Number Wireless Connectivity Protocol Memory Package Size Hardware Development Tool
MKW41Z512VHT4 Bluetooth Low Energy and IEEE 802.15.4 512 KB Flash,
128 KB RAM
7 mm x 7 mm x 1 mm
48-pin Laminate QFN
MKW41Z256VHT4 256 KB Flash,
MKW41Z512CAT4R 512 KB Flash,
128 KB RAM
3.9 mm x 3.8 mm
75-pin WLCSP
MKW31Z512VHT4 Bluetooth Low Energy 512 KB Flash,
128 KB RAM
7 mm x 7 mm x 1 mm
48-pin Laminate QFN
MKW31Z256VHT4 256 KB Flash,
MKW31Z512CAT4R 512 KB Flash,
128 KB RAM
3.9 mm x 3.8 mm
75-pin WLCSP
MKW21Z512VHT4 IEEE 802.15.4 512 KB Flash,
128 KB RAM
7 mm x 7 mm x 1 mm
48-pin Laminate QFN
MKW21Z256VHT4 256 KB Flash,

MCUXpresso Software and Tools

MCUXpresso Config Tools – A comprehensive suite of system configuration tools, including pins, clocks, SDK builder and more.

MCUXpresso SDK – An open-source software development kit (SDK) built specifically for your processor and evaluation board selections.

MCUXpresso IDE – An easy-to-use integrated development environment (IDE) for creating, building, debugging, and optimizing your application.

Protocol Stacks

Connectivity Software

Kinetis Connectivity Software Version 1.0.1 includes the following components:

  • KW40Z Bluetooth® low energy v4.2 stack, v1.1.4
  • KW40Z IEEE® 802.15.4-2006/2011 MAC/PHY implementation v5.2.4
  • KW40Z Simple Media Access Controller (SMAC) v3.2.4
  • KW40Z-enabled Connectivity Framework

NXP Designs: Reference Design Library

Technical content and expertise to help jump start your design and get you to production faster.


Quick reference to our documentation types.

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Design Resources

Design Files

1 design file

  • Design Files - miscellaneous

    KW41Z/31Z/21Z Design in check-list


5 hardware offerings


1-5 of 10 software files

  • Development IDEs and Build Tools

    Design Studio Integrated Development Environment (IDE)Featured

  • BSPs and Device Drivers


  • Connectivity Software

    Kinetis KW41Z Connectivity Software

  • Connectivity Software

    Test Tool for Connectivity Products

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Note: For better experience, software downloads are recommended on desktop.

Engineering Services

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To find a complete list of our partners that support this product, please see our Partner Marketplace.


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