Proving the Business Case for the Internet of Things

Maxim microcontroller takes third off IoT costs

Steve Rogerson
July 29, 2020



A low-power dual-core microcontroller from California-based Maxim Integrated uses Bluetooth LE 5.2 and is claimed to help cut costs by up to a third for IoT applications.
 
The Max 32666 with wireless connectivity can extend battery life and shrink the size of coin cell-operated devices.
 
Designers of wirelessly connected, coin cell-operated IoT products can reduce costs while also saving space and battery life with the microcontroller. This dual Arm Cortex-M4 MCU with floating-point unit and BLE 5.2 extends the device’s battery life by combining robust memory, security, communications, power management and processing functions traditionally performed by multiple MCUs into a single device.
 
As IoT applications advance, more MCUs are typically added to the system. Usually these systems include a dedicated processor to handle the application, another processor acting as a sensor hub, a separate standalone BLE microcontroller to handle the wireless connectivity function and, in many cases, a power management IC to provide supply voltages efficiently to the MCUs.
 
However, this approach is proving to be unsustainable for IoT applications that are growing in complexity while still demanding smaller size and longer battery life.
 
The Max 32666 has been added to Maxim’s smart, function-rich Darwin family of MCUs. In contrast to traditional architectures, this MCU reduces form factor and design footprint, enabling IoT device designers to lower costs by consolidating up to three sockets found in their current designs.
 
It provides computation of complex functions, operating at up to 96MHz, which can speed up data processing by 50 per cent.
 
To replace the need for a separate power management IC, it has an integrated single-inductor, multiple-output regulator, which extends the life for small-sized battery applications.
 
BLE 5.2 support is for up to 2Mbit/s of data throughput and long range (125 and 500kbit/s) and offers transceiver output power of +4.5dBm programmable down to -95dBm. It also protects applications from cyber-security threats with a trust protection unit and big maths acceleration for fast elliptic curve digital signature algorithm.
 
The IC’s hardware accelerators provide AES-128, -192 and -256 encryption, while TRNG seed generator and SHA-2 accelerator enhance security. It also protects IP firmware with a secure boot loader.
 
On-board memory capacity is up to 1Mbyte flash memory and 560kbyte of SRAM with optional error correcting code for more robust applications, as well as multiple high-speed peripherals. It is said to manage more data and accommodate bigger applications without running out of code space through efficient operation within a best-in-class power profile.
 
Features include:

  • Reliability: Adds an extra level of robustness with integrated ECC on flash, SRAM and cache memories, preventing undesirable bit flips.
  • Cost: Combines two microcontroller cores, a Bluetooth radio with dedicated stack core, power management, security and memory into one IC. This reduces costs by making use of dual 96MHz Cortex-M4 with floating-point unit as well as on-board memory of 1Mbyte flash and 560kbyte SRAM.
  • Board space: Integrates multiple functions into a single IC with 3.8 by 4.2mm WLP footprint.
  • Power: Preserves battery life of coin-cell battery devices through low active-mode power. It offers dynamic voltage scaling for reduced active core power consumption and enables 27.3µA/MHz at 3.3V executing from cache memory. Multiple power down modes support longer battery life, achieving 1.2µA at 3.3V in the lowest power mode.
“The robust installed base of IoT devices is expected to grow at a CAGR of 12 per cent per year through 2030 from 2015, when it will reach more than 80 billion units,” said Julian Watson, principal analyst for IoT at market watcher Omdia. “The critical component for sustaining the growth rate is the continued ability to add functionality for these devices while improving efficiency so that end-users will appreciate their value and convenience. Clearly, Maxim Integrated is aiming to advance IoT ubiquity with its new family of Darwin microcontrollers.”
 
The Max 32666GWPBT+ is available from Maxim’s web site for $5.22, 1000-up, FOB USA, and is also available from authorised distributors. The Max 32666EV Kit# is available on Maxim’s web site for $157.50.
 
“It’s possible to keep adding microcontrollers to any IoT application, but frequent battery replacements conflict with end-user utility and convenience,” said Kris Ardis, executive director at Maxim Integrated. “By applying the power-saving advantages of wearable technology to the broader spectrum of IoT applications, this new family of processors reduces battery replacements and improves computing performance.”