Courtesy of Nordic Semiconductor : Power management solution for Bluetooth Low Energy IoT applications reduces Nordic SoC sleep mode power consumption increasing battery life up to 10x
Nanopower’s ‘nP-BLE52 module’ can reduce the power consumption of Nordic’s nRF52832 SoC to 10nA in sleep mode and wake up the chip on a predetermined schedule or based on sensor threshold values
The nP-BLE52 module employs a proprietary power management IC—integrated alongside Nordic’s nRF52832 Wafer-Level Chip Scale Package (WL-CSP) SoC in a System-in-Package (SiP)—which enables it to cut power to the SoC, putting it in sleep mode, before waking it up a pre-set time and in the same state as before it was put to sleep. In doing so the SoC’s power consumption in sleep mode is reduced to 10nA, making it ideal for IoT applications where battery life is critical by potentially increasing cell lifespan 10x.
In active mode, the nRF52832 SoC runs normally. The SoC has been engineered to minimize power consumption with features such as the 2.4GHz radio’s 5.5mA peak RX/TX currents and a fully-automatic power management system. Once the Nordic SoC has completed its tasks, it instructs the nP-BLE52 to put it to sleep and wake it up again at the pre-set time. The nP-BLE52 then stores the Nordics SoC’s state variables and waits until the nRF52832 SoC needs to be powered up again. On wake-up, the device uploads the previous state variables, allowing the Nordic SoC to be restored to the same operational state as before the power was cut. The SoC’s start-up is much more rapid than if it was activated from a non-powered mode.
The nP-BLE52 ‘module’ also features a low power MCU which can be set to handle external sensors and actuators when the Nordic chip is switched off. In this state, the module still monitors sensors and buffer readings and can trigger wake-ups if these readings are above predetermined thresholds, while consuming less less than 1uA. The nP-BLE52 also integrates an embedded inertial measurement unit (IMU).
The module’s power management is controlled through a simple API, whereby the user can predetermine the duration of the Nordic SoC’s sleep mode, set the wake-up time and date parameters, and select pins for other on/off triggers.
The nRF52832 WL-CSP SoC measures just 3.0 by 3.2mm while offering all the features of the conventionally-packaged chip. The nRF52832 is a powerful multiprotocol SoC ideally suited for Bluetooth LE and 2.4GHz ultra low-power wireless applications. It combines an 64MHz, 32-bit Arm® Cortex™ M4F processor with a 2.4GHz multiprotocol radio (supporting Bluetooth 5, ANT™, and proprietary 2.4GHz RF software) featuring -96dB RX sensitivity, with 512kB Flash memory and 64kB RAM.
The WL-CSP SoC is supplied with Nordic’s S132 SoftDevice, a Bluetooth 5-certifed RF software protocol stack for building advanced Bluetooth LE applications. The S132 SoftDevice features Central, Peripheral, Broadcaster, and Observer Bluetooth LE roles, supports up to twenty connections, and enables concurrent role operation. Nordic’s unique software architecture provides clear separation between the RF protocol software and the developer’s application code, easing product development.
“While Nanopower sought to dramatically improve power consumption when not transmitting, we selected the nRF52832 because it is the best in class for TX/RX efficiency,” says Tore Irgens Kuhnle, CEO, Nanopower. “The WL-CSP packaging was also important because it allowed us to create a small footprint module.
“We know Nordic very well, and in our experience, support has always been fast and helpful.”