KW39/38/37: 32-Bit Bluetooth 5.0 Long-Range MCUs with CAN FD and LIN Bus Options, Arm® Cortex®-M0+ Core


Click over video to play

Block Diagram

KW39/38/37 MCUs Block Diagram

KW39/38/37 MCUs Block Diagram


MCU and Memories

  • Up to 48 MHz Arm Cortex-M0+ core
  • Nested Vectored Interrupt Controller (NVIC)
  • Wake-up Interrupt Controller (WIC)
  • Single wire debug (SWD) and micro trace buffer
  • KW37: 512KB program flash memory w/ ECC
  • KW39/38
    • 256KB program flash memory plus 256KB FlexNVM w/ ECC
    • 8KB FlexRAM supporting EEPROM emulation
  • On-chip 64KB SRAM
  • Security circuitry to prevent unauthorized access to RAM and flash contents through the debugger

Radio and Features

  • 2.4 GHz Bluetooth Low Energy Version 5.0 radio supporting up to 8 simultaneous hardware connections in any central/peripheral combination
  • Generic FSK modulation:
    • Data Rates: 250, 500 and 1000 kbps
    • Modulations: GFSK BT = 0.3, 0.5, 0.7, 1.0; FSK/MSK
    • Modulation Index: 0.32, 0.5, or 0.7
  • High Speed (2 Mbps), Long Range, Advertising Extensions
  • -98 dBm receiver sensitivity in BLE 1Mbps mode
  • -105 dBm receive sensitivity in BLE long range 125kbps mode
  • -101 dBm typical generic FSK (at 250 kbit/s) sensitivity
  • Programmable Transmitter Output Power: -30 dBm to +5 dBm
  • Low external component counts for low cost application and reduced form factor
  • On-chip balun with single ended bidirectional RF port
  • Supports transceiver range extension using external PA and/or LNA
  • Enhanced Bluetooth LE automatic deep sleep modes (DSM) supporting Peripheral Latency

Low Power Consumption

  • Transceiver current (DC-DC buck mode, 3.6 V supply)
    • Typical Rx current: 6.3 mA
    • Typical Tx current: 5.7 mA @ 0 dBm output
  • Low Power Mode (VLLS0) Current: 250 nA


  • 26 MHz and 32 MHz supported for Bluetooth LE and Generic FSK modes
  • 32.768 kHz Crystal Oscillator

Operating Characteristics

  • Voltage range: 1.71 V to 3.6 V
  • Ambient temperature range: –40 to 105 °C
  • AEC Q100 Grade 2 Automotive Qualification (KW39A/38A/37A)
  • Industrial Qualification (KW38Z/37Z)

Human-Machine Interface

  • General-purpose input/output w/ interrupt capability

System peripherals

  • Nine MCU low-power modes to provide power optimization based on application requirements
  • DC-DC Converter supporting Buck and Bypass operating modes
  • Direct memory access (DMA) Controller
  • Computer operating properly (COP) watchdog
  • Serial wire debug (SWD) Interface and Micro Trace buffer
  • Bit Manipulation Engine (BME)

Analog Modules

  • 16-bit Analog-to-Digital Converter (ADC)
  • 6-bit High Speed Analog Comparator (CMP)
  • 1.2 V voltage reference (VREF)


  • 16-bit low-power timer (LPTMR)
  • 3 Timers Modules(TPM) with PWM capability: One 4- channel TPM and two 2-channel TPMs
  • Programmable Interrupt Timer (PIT)
  • Real-Time Clock (RTC)

Communication interfaces

  • 2 serial peripheral interface (SPI) modules
  • 2 inter-integrated circuit (I2C) modules
  • Low Power UART (LPUART) module with LIN support (2x LPUART on KW38)
  • Carrier Modulator Timer (CMT)
  • FlexCAN module (with CAN FD support up to 3.2 Mbps baudrate) on KW38


  • AES-128 Hardware Accelerator (AESA) with LTC
  • True Random Number Generator (TRNG)
  • Advanced flash security on Program Flash
  • 80-bit unique identification number per chip
  • 40-bit unique media access control (MAC) sub-address
  • LE Secure Connections


  • 7 x 7 mm 48HVQFN with “Wettable” flanks and is pin and package compatible with KW36/35/34 family

Part numbers include: MKW37A512VFT4, MKW37Z512VFT4, MKW38A512VFT4, MKW38Z512VFT4, MKW39A512VFT4.


Quick reference to our documentation types.

1-5 of 27 documents

Show All


1-5 of 9 hardware offerings

Show All


1-5 of 9 software files

Show All

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

Engineering Services

2 engineering services

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