New-Tech Europe Magazine | H2 2023

How to Greatly Improve Battery Power Efficiency for IoT Devices

Suryash Rai, Product Applications Engineer, ANALOG DEVICES

Abstract This article explores how to make Internet of Things (IoT) devices more power efficient. It covers a quick refresher of battery management before focusing on the critical role of nanopower ship mode and sleep mode. Finally, it provides a new solution that better optimizes these two aspects of battery management, which reduces the power consumption levels and board space over traditional methods. Introduction In the connected world of the internet, the IoT plays a crucial role by connecting different sensing nodes and transmitting the data to a secure server. Power management is one of the focus areas to increase the efficiency of the IoT application. In most applications, the sensor node (data acquisition element) is placed in a remote area and powered by

a battery. The life of the battery depends on how efficiently we design the power strategies for the sensor node. Most of the time, the sensor node stays in sleep mode and switches to active mode only when it requires data acquisition. The duty cycle of these devices is low. To maximize the battery life, we need to improve the sleep current of IoT applications. The Basics of Power Management in an IoT Device In a typical IoT system, as shown in Figure 1, the wireless sensor node is mostly battery operated and, thus, inherently constrained by battery life. To maximize the life of the sensor node, power management is crucial. The duty cycle concept is a common practice for saving power in a sensor node. Since overhearing and idle listening are major sources of energy

wastage in the sensor node, we can evaluate a wireless sensor node’s power consumption using three different areas: Sensor The sensor collects the raw data like temperature and humidity and sends this data to the microcontroller. The microcontroller processes the raw data and transmits this data to the cloud or data center using a radio link. However, given that typical sensor applications operate at very low duty cycles (ranging from 0.01% to 1%) and are idle most of the time, adopting a power management scheme where sensor node sleep current is ultralow will conserve battery life. A smart irrigation system where the sensor node measures the soil moisture and collects data only once per hour is an example of such an application. Microcontroller Radio operation

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