NXP presented two new wireless microcontrollers on 27 October 2026: the MCX W70 for industrial and IoT products and the KW43 for cars. Both support Bluetooth Channel Sounding, the Bluetooth 6.0 feature that measures the distance between two devices. The MCX W70 is the one smart home makers will look at, because its radio also runs Zigbee, Thread for Matter and Aliro, the new standard for opening doors with a phone.

Cheaper versions of last year's chips

NXP's first Channel Sounding parts came out in 2025: the KW47 for cars and the MCX W72 for industrial and IoT use. The new pair is the cost-down branch of the same platform, meant for products where price, size or power use is the tight limit. The KW47 and MCX W72 stay for designs that need more headroom.

The saving comes from how security is built. The older chips put NXP's EdgeLock security functions in a separate hardware enclave with its own memory. In the KW43 and MCX W70, much of that runs in IP blocks and software, and the cores share one memory. NXP says this does not weaken anything, and the new chips are certified one level higher than their predecessors, at SESIP Level 3 and PSA Level 3. The certification list also includes CE RED, the EU radio rules that now carry cybersecurity requirements, and IEC 62443. NXP describes both chips as ready for post-quantum cryptography.

The MCX W70 product page fills in the hardware. There are two 96 MHz Arm Cortex-M33 cores, one for the application and one for the radio, with 1.5 MB of flash and 256 kB of SRAM. Bluetooth LE and 802.15.4 (Thread, Zigbee) can run at the same time, deep sleep with full RAM retention draws about 4 µA, and the chip comes in a 7 x 7 mm QFN48 or a 5 x 5 mm BGA package.

What Channel Sounding is for

Channel Sounding combines round-trip time and phase-based ranging to work out distance. That is harder to fool than signal strength, which most Bluetooth "proximity" features use today. NXP quotes 20-50 cm accuracy for the MCX W70. The uses that matter at home:

  • smart locks and digital keys that open only when the phone is really at the door,
  • item trackers that show distance rather than just "nearby",
  • presence and room detection.

A dedicated localization compute engine on the chip runs the ranging algorithms, and NXP says it does so nearly 45% faster than without it.

The KW43 is AEC-Q100 Grade 2 qualified and has CAN and LIN for in-car networks, aimed at phone-as-key systems. For smart home readers it mostly shows where this technology is heading: the ranging that unlocks a car is being made cheap enough for door locks and sensors.

When it arrives

Both chips are sampling now and NXP offers evaluation kits. Broad availability is targeted for the second quarter of 2027, so finished products will come later than that. NXP did not publish prices.

The MCX W70 has company. Nordic announced the nRF54LC10A in September, another small multiprotocol chip with Channel Sounding, Thread, Zigbee and Matter, so device makers will have several low-cost options in 2027.