NXP MCX W70 and KW43 wireless MCU families support Bluetooth 6.x Channel Sounding for secure distance measurement in industrial IoT and automotive applications. The MCX W70 supports Bluetooth LE, Zigbee, Thread, and Matter for Smart Home and industrial devices, while the KW43 is designed for automotive applications such as digital keys and secure vehicle access.
Both families feature a 96 MHz Arm Cortex-M33 application core, a separate Cortex-M33 core for wireless connectivity, up to 1.5MB flash, 256KB SRAM, a dedicated Localization Compute Engine (LCE), and NXP’s EdgeLock security features. Bluetooth Channel Sounding support combines phase-based ranging (PBR) and round-trip time (RTT) to improve distance measurement accuracy and security.
NXP MCX W70 and KW43 key features and specifications:
- MCU cores
- Application core – Arm Cortex-M33 @ 96 MHz with FPU, MPU, DSP/SIMD instructions, and TrustZone-M
- Radio subsystem – Arm Cortex-M33 @ 96 MHz
- Accelerator – Localization Compute Engine (LCE) for Bluetooth Channel Sounding
- Memory
- MCX W70
- 1.5 MB shared flash with ECC
- 256 KB shared SRAM with ECC and parity
- 20 KB LCE-Lite SRAM and 320 KB ROM
- KW43
- Up to 1.5 MB shared flash
- 256 KB SRAM
- MCX W70
- Wireless connectivity
- Common – Bluetooth LE 6.x with Bluetooth Channel Sounding (BCS), using phase-based ranging (PBR) and round-trip time (RTT) for secure distance measurement
- MCX W70
- 20–50 cm ranging accuracy, as specified by NXP
- IEEE 802.15.4 supporting Zigbee, Thread, Matter, and dual PAN operation
- IEEE 802.15.4j Medical Body Area Network (MBAN) support in the 2360–2400 MHz band
- Concurrent Bluetooth LE and IEEE 802.15.4 operation, with support for proprietary FSK/GFSK/MSK/GMSK protocols
- Integrated 2.4 GHz radio with LNA/PA and 32 MHz crystal oscillator
- KW43
- Bluetooth LE 6.x with up to 10 simultaneous connections
- Proprietary 2.4 GHz
- Wi-Fi coexistence
- Peripherals
- Up to 32x GPIO with 2x LPUART, 3x LPSPI, 2x LPI²C, 1x optional CAN FD (MCX W70)
- Analog (MCX W70)
- 1x 16-bit ADC
- 1x low-power analog comparator
- Internal temperature sensor
- Timers and system control (MCX W70)
- 5x 32-bit TPM timers with PWM support
- 2x low-power timers
- 2x watchdog timers
- Real-time clock (RTC)
- 16-channel DMA controller
- Signal frequency analyzers
- System Power Controller (SPC) and Trusted Resource Domain Controller (TRDC)Peripherals
- KW43 – CAN and LIN connectivity for automotive applications
- Security
- EdgeLock 2GO cloud-based key and certificate management (MCX W70)
- Secure boot and debug, Arm TrustZone-M
- AES, SHA, RSA, and ECC cryptographic acceleration
- True random number generator (TRNG)
- Hardware root of trust and secure key management
- Post-quantum cryptography (PQC) support
- PSA Level 3 and SESIP Level 3 security
- PQC-ready architecture, with SM2, SM3, and SM4 cryptographic support listed for the MCX W70
- Digital tamper pins, glitch detection, flash access protection, and Intrusion and Tamper Response Controller (ITRC) (MCX W70)
- Power (MCX W70)
- 1.8V to 3.6V supply
- Integrated DC-DC converter and LDO regulators
- Around 4 µA deep sleep current with 256KB RAM retention
- Package (MCX W70)
- 48-pin QFN (7 × 7 mm)
- 64-ball MAPBGA (5 × 5 mm)
- Operating temperature – -40°C to +125°C junction temperature
- Qualifications – AEC-Q100 Grade 2 qualification, automotive CAN/LIN connectivity, and support for digital car keys and secure vehicle access (KW43 only)
The KW43 has many common features with MCX W70, including dual Cortex-M33 cores, 1.5MB shared flash, 256KB SRAM, Bluetooth 6.x Channel Sounding, and EdgeLock security. However, the KW43 is designed for automotive applications and is qualified to AEC-Q100 Grade 2. It supports up to 10 simultaneous Bluetooth LE connections, proprietary 2.4 GHz wireless protocols, and CAN and LIN interfaces. At the time of writing, information about the KW43 SoC is limited, but some technical details are available through the NXP KW43 Knowledge Hub, along with early SDK documentation.
Both MCUs are supported by NXP’s MCUXpresso development environment, including MCUXpresso for VS Code, MCUXpresso IDE, the MCUXpresso SDK, wireless protocol stacks, and software examples. The FRDM-MCXW70 and FRDM-KW43 development boards will also be offered with onboard MCU-Link debug probes, CAN/LIN transceivers, sensors, buttons, LEDs, Arduino-compatible headers, and MikroE Click expansion connectors.
The company also designed the MCXW70-LOC and KW43-LOC boards specifically targeting Bluetooth Channel Sounding and localization development. The FRDM-MCXW70 uses the MCXW70ACMFT, while the FRDM-KW43 and KW43-LOC boards use the KW43B43ZC7MFT MCU. NXP’s early SDK documentation mentions that some Bluetooth LE and Channel Sounding features are still undergoing validation.
Previously, we have written about the MCX W72 for industrial IoT applications and the KW47 for automotive applications. Compared to the MCX W72, which has 2MB application flash, 512KB radio flash, and separate SRAM banks, the new MCX W70 uses a unified memory architecture with 1.5MB flash and 256KB SRAM shared between the application and radio cores. The new MCUs also use a more integrated EdgeLock security architecture instead of a separate hardware security enclave, helping reduce chip complexity and cost.
The MCX W70 also supports Aliro, a smart-access interoperability standard designed for secure digital credentials and access control, and NXP also promises a software-upgradeable radio subsystem and 15-year product longevity for the MCX W7x family.
The MCX W70 and KW43 wireless MCUs are in pre-production and sampling phases, and mass production is expected in Q2 2027. Pricing has not been officially announced, but one KW43 variant, the KW43L43Z96MFTBR, appears to be sold/listed for $4.52 on Digi-Key for 2K orders. More information is available on the MCX W70 product page and in NXP’s announcement.
Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication
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