Many IoT products require secure, always-on connectivity (often via Wi-Fi), but that almost always comes at the cost of compromises in terms of battery life.
Dialog Semiconductor announced the availability of the DA16200, an ultra-low-power Wi-Fi networking SoC, along with two modules that leverage Dialog’s VirtualZero technology to deliver a longer battery life for Wi-Fi-connected, battery-powered IoT devices. This SoC has integrated power amplifiers (PA) and low noise amplifiers (LNA), so there is no need for an external PA. The PA’s output power is +20dBm when required. Meanwhile, LNA delivers -99.5dBm receiver sensitivity.
“Dialog’s VirtualZero technology enables a device to join and stay connected to a Wi-Fi network at a very low average current to enable longer battery life — typically over a year, and in many cases three- to five years,” said David Cohen, senior marketing director at Dialog’s Audio and Connectivity Business Unit.
“Most of our customers’ applications utilize small batteries such as AAAs, AAs, and rechargeable lithium ions or use coin cells,” Cohen continued. “However, it is possible to leverage energy harvesting if the energy harvesting device can produce an output power of about 85mA. That type of output power is only needed when in active Tx mode. With VirtualZero, devices can maintain Wi-Fi connectivity at as little at 200nA (0.2uA).”
Analog/digital mixed integrated circuits are smaller and more energy-efficient compared to their equivalent designs using discrete components, but those benefits come at the cost of greater design complexity. It’s not easy to make and test devices that integrate digital, analog, and radio frequency circuitry.
If you want to build a vast sensor network, the battery must last a long time so that maintenance costs remain within reasonable limits. To reduce energy consumption, many IoT device designers adopt various strategies, such as a shallow duty cycle or the use of different idle and sleep modes.
“From an engineering perspective, it’s important to look at a few key factors. A major factor is the total average current the device needs to consume to maintain a Wi-Fi connection. For most IoT applications, there isn’t a lot of true active traffic. For example, a typical smart door lock only sends/receives real payload data (open the lock, close the lock, respond with lock status) about 1-20 times per day. More than 99% of the time it is sitting idle in a ‘Wi-Fi ready’ state — connected to the Wi-Fi network burning current, but not exchanging any real data. That idle time is exactly what drains battery life. So, if you can get the total average current down to a very low rate in a Wi-Fi ready state, you will be able to extend battery life. In reality, the active Tx and Rx current matters very little for these applications,” said Cohen.
In higher performance devices, the processor, display, and wireless communication interfaces take up most of the available energy budget. Understanding how these devices use energy means modeling the interaction between their subsystems to understand each other’s influences and the behavior of their power management systems.
“Another consideration is range — can the Wi-Fi device achieve the output power and receiver sensitivity required to maintain a Wi-Fi network connection in a realistic, busy environment? The range is often more important for many IoT devices than it is for a mobile device like a laptop. If your laptop’s Wi-Fi connection is flaky, you can try to move a few feet and see if the connection improves. But a door lock cannot move, and neither can thermostats, sensors, etc,” said Dialog’s Cohen.
The operating life of devices installed and left unattended can be extended by using new battery technologies, energy harvesting, ultra-low-power electronic circuits and communication strategies designed to limit energy consumption.
DA16200 SoC (Image: Dialog)
The common element in IoT devices is their daily use by consumers. These technologies have often underestimated the aspects related to both physical and computer security: what is worrying is not only what’s related to the collection of data, their sharing and tampering by third parties but also the possibility that these objects can be controlled and managed remotely by malicious parties.
The DA16200 SoC and modules are equipped with industry-leading security protocols, including the latest generation hardware encryption engine and authentication standards for safeguarding against potential threats.
“Strong security features are essential for IoT and for any Wi-Fi connected device. We have multiple security layers in the DA16200 SoC, including the Wi-Fi layer – WPA2 and WPA3 – both personal and enterprise modes are supported, and with Extensible Authentication Protocol ( EAP) support. Transport Layer Security (TLS) in hardware – this enables accelerated TLS connections directly from the SoC to cloud servers such as Amazon Web Services (AWS), Azure, Google Cloud, and more. Moreover, it turns an ordinary, insecure HTTP connection into an HTTPs secured connection. Additional encryption tools include long Advanced Encryption Standard (AES) keys, accelerated Diffie-Helman, hash functions, and elliptic curve encryption. Secure boot – we authenticate the software image every time before loading it. Secure debug via JTAG or Serial Wire Debug (SWD). Secure asset storage – the customer can burn in license keys, digital certificates, and much more with our secure One-time password (OTP),” said Cohen.
The development possibilities of the IoT are multiple, and the connected devices will be increasingly compatible with each other, increasing interoperability and integration, without neglecting cybersecurity and privacy aspects. There will also be greater convergence between big data, IoT, and AI: more and more data – in real-time – will be collected and, thanks to advanced analytics technologies, products, services, and systems will become increasingly “intelligent” and competitive.
>> This article was originally published on our sister site, EE Times.