In the past year, NXP has made significant strides in hardware for IoT technology. One of particular interest is NXP's recently announced family of multiprotocol, ultra-low-power MCUs targeted at eco-friendly smart home devices.
The K32W061. Image used courtesy of NXP
This announcement comes at a time when developers are increasingly interested in the notion of multi-protocol devices for design versatility and power savings.
NXP and Other Suppliers Hunker Down on Wireless
NXP is one of many semiconductor leaders making wireless-focused acquisitions. Last year, NXP cashed out $1.76 billion to acquire Marvell’s Wi-Fi and Bluetooth and BLE portfolio—following suit of, for example, Dialog Semiconductor's acquisition of Silego for $306 Million in bid for IoT.
Then, this year, Silicon Labs shelled out $308 million in cash to acquire Redpine Signals' connectivity business. This acquisition was especially significant, given Redpine Signals' claim to the first multi-protocol wireless chipsets for IoT.
NXP likewise has recently released its own family of multi-protocol ultra-low-power MCUs targeted at eco-friendly smart home devices. The specifics of this device can tell us about the design preferences of an IoT-focused market.
Basic Features
The K32W041 and K32W061 are built around Arm Cortex M4 MCU cores clocked at 48 MHz. 640 KB of onboard flash memory and 152 KB of SRAM allows for over-the-air (OTA) software updates as well as complex internal applications.
Block diagram for the K32W061/41 family. Image used courtesy of NXP
The family members are available in a 6 mm x 6 mm HVQFN40, 0.5 mm pitch package that is lead-free and RoHS compliant. The junction temperature range is -40℃ to +125℃.
The Benefits of a Multi-Protocol Device
The K32W061/41 feature an IEEE 802.15.4 radio that supports BLE 5.0 and both the Thread and Zigbee networking protocols. Additionally, the KW32W061 features an integrated NFC NTAG.
The new units are said to augment the company’s recently-released wireless MCUs for Thread and Zigbee and NXP's new BLE MCUs, which are part of an IoT portfolio that includes BLE, Thread, Zigbee, and Wi-Fi capabilities.
Both units support Bluetooth Low Energy 5.0, Zigbee, and OpenThread wireless network protocol stacks. With no need for separate devices to support each protocol, board space is conserved and critical BoM costs are appreciably lowered for small, price-sensitive applications.
Communication and Security
Additionally, the KW32W061 NFC NTAG capability simplifies the pairing process through the support of standardized out-of-band communications. Longer distance communication is enabled by the multiprotocol radio’s integration of a power amplifier, which can generate up to + 11 dBm of output power.
The units include two SPI interfaces, two UARTS, and two I2C interfaces. There is also a DMIC subsystem that includes a dual-channel PDM microphone interface that supports a voice activity detector.
Security features include a 128-bit, 192-bit, or 256-bit AES security processor and a random number generator. There is also a hash hardware accelerator that supports SHA-1 and SHA-256.
Additional Radio Features
- The receiver draws 4.3 mA
- IEEE 802.15.4 and BLE receiver sensitivity is -100 dBm and -97 dBm, respectively.
- Transmit power requirements for +10 dBm, +3 dBm and 0 dBm outputs are 20.3 mA, 9.4 mA and 7.3 mA, respectively.
- Sata rate for BLE is 2 Mb/s
Radio architecture of the K32W061/41. Image used courtesy of NXP
A Single Coin Cell Battery
Lowering the power requirements for both smart home and industrial IoT applications is a key to enabling a device to run for a multi-year span on a single-coil cell battery without recharging. NXP says its K32W041/61 family allows OEMs to achieve this goal through its low transmit/receive radio power drains and multiple low-power modes.
“The demand for ultra-low power connectivity in the smart home continues to grow as does the number of wireless technologies to choose from,” said Tom Pannell, senior marketing director for connectivity solutions at NXP.
He goes on to state, “With the launch our new multiprotocol wireless microcontrollers, NXP is providing ultra-low-power performance for connected applications by leveraging the breadth and expertise of our technology portfolio to deliver solutions that make it easier for OEMs to design robust and feature-rich Internet of Things devices with Bluetooth LE, Zigbee, and Thread.”
Support Tools
The IOTZTB-DK006 is a development kit applicable to both the K32W061 and the JN5189/88.
IOTZTB-DK006. Image used courtesy of NXP
With this kit, users can assemble a small wireless network to explore multi-protocol applications.
Around the Industry
What applications can we expect to see from NXP's new multi-protocol MCUs—and other devices like it? NXP lists several use cases:
- Access control and security
- Home and building automation
- Gateways and sense sensor networks applications
- Smart thermostats and smart locks
Application of K32W041/61 for a battery-powered solution. Image used courtesy of NXP
Another option for a multi-protocol device includes Silicon Labs' EFR32MG21 series two multi-protocol wireless SoCs. These devices are based on the Arm Cortex M33. They support Zigbee, Thread, and Bluetooth long-range with up to +20 dBm output power.
Designers of wireless solutions might also consider the STM32WB from STMicroelectronics, which is IEEE 802.15.4 compliant and supports BLE 5.0, Zigbee, and Thread. The 64 MHz device is based on the Arm Cortex-M4.