Hands-On Experience with the High-Efficiency PMIC nPM1300 Evaluation Kit
1. Introduction
Recently, I received a board sent by the Breadboard Community, which is based on Nordic’s latest nPM1300 power management chip evaluation kit. When it comes to power management chips, many people may be familiar with discrete chips, such as buck-boost, power monitoring, POR reset, and charge-discharge management functions, but it is rare to see all these functions integrated into a single chip. In this article, we will experience the first-ever power management IC (PMIC) that integrates all the necessary functions—nPM1300.
The Breadboard Community is currently applying for the nPM1300
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2. Nordic Semiconductor
nPM1300 is a PMIC power management chip from Nordic, which was founded in 1983. Those involved in the development of Bluetooth low-power products should be familiar with it. It is a pioneer in ultra-low-power wireless technology and a representative enterprise in the field of wireless technology.Nordic is headquartered in Norway and has technologies such as Bluetooth, ANT+, Thread, Zigbee, WiFi, and NB-IoT.Nordic’s low-power Bluetooth SoCs are widely used in IoT applications, including wireless PC peripherals, gaming, sports and fitness, mobile accessories, consumer electronics, toys, healthcare, and automation products.Although many SoCs have integrated power management functions, due to constraints in power consumption, efficiency, and charge-discharge management, many users still need external power management chips to meet complex functional requirements. Common power management chip architectures are usually quite simple, generally supporting multiple adjustable voltage outputs and external battery charge-discharge management.With the increasing demands for product size, performance, and battery life in smart homes and wearable products, the functionalities of power management chips have also increased, such as:
Hardware reset needed in abnormal situations
Longer battery life
Accurate battery level statistics
Fast and safe charge-discharge
Smaller size and higher efficiency
The power management IC we are going to evaluate in this article—the nPM1300—includes all of the above functions.
3. nPM1300 Evaluation Kit Hardware Resources
Like many of Nordic’s development boards and evaluation boards, the nPM1300 evaluation kit also adopts a cyan PCB design. The overall size of the board is 100mm long and 64mm wide, using a 4-layer PCB design, based on Altium Designer design software.The official provides all hardware documentation, such as PCB and schematics, drilling files, BOM, Gerber, and placement files required for production design. Let’s take a detailed look at the hardware resources of the board:
nPM1300 core chip, QFN32 package, all pins are led out through standard 2.54mm pitch pin headers for flexible evaluation and measurement
1 SHPHLD button, 3 GPIO tactile buttons, 3 LED indicators
Supports two types of battery interfaces, with and without NTC
The main control chip is nRF5340, connected to the host computer via USB serial and configured the nPM1300 registers via IIC communication
Two USB-C interfaces, one connects to nRF5340 for USB serial functionality, the other connects directly to nPM1300
Multiple voltage test points for easy connection using an oscilloscope or multimeter
A set of external expansion interfaces can be used to connect compatible power meter expansion boards
The system block diagram of the nPM1300 evaluation kit is as follows:Top and bottom layers of the PCB3D effect of the PCB:Close-up of the nPM1300 chipUSB-C interfaceOnboard 3 user buttonsLEDBattery interfacePins are led out through pin headersThe expansion interface can connect to the power meter expansion board shown in the figure below, used to generate the charge-discharge model of the battery.
4. Introduction to nPM1300 Chip Features
After understanding the hardware resources of the evaluation board, let’s focus on the core of this board—the nPM1300 chip.From the official data sheet, we can see the internal structure of the chip:It mainly includes the following parts:
DC-DC BUCK converter
Battery charge-discharge management section
GPIO and LED drive section
Digital interface bus section
Load switch section
The detailed electrical characteristics of nPM1300 are as follows:
Two ultra-efficient DC-DC buck outputs, adjustable from 1.0-3.3V, with a maximum output of 200mA
Charging current adjustable from 32-800mA, step size 2mA, supports NTC input, output voltage from 3.5V to 4.45V
No limit on battery capacity, supports lithium-ion, lithium-polymer, and lithium iron phosphate batteries
Two 100mA load switches or 50mA LDO, supports voltage from 1.0-3.3V
Supports USB Type-C interface, CC pins can be directly connected to chip pins, with built-in 5.1k pull-down resistor, no external configuration required
Input voltage from 4.0-5.5V, maximum 1.5A, with 22V over-voltage protection
5 configurable GPIOs, 3 configurable LED outputs
Fully compatible I2C TWI digital bus interface, supports speeds up to 400KHz
Manufactured with 180nm process, operating temperature range -40℃ to 85℃, PN junction temperature less than 125℃
Two hardware resets, watchdog timer, wake-up timer, general-purpose timer
10-bit precision ADC used to measure input voltage, battery voltage, current, and chip temperature
Supports power statistics function, sampling battery voltage, current, and temperature values through internal ADC, enabling precise power statistics through official algorithms
Over-voltage, under-voltage, over-current protection, temperature protection
Ultra-small package sizes: 3.1×2.4 mm WLCSP and 5.0×5.0 mm QFN
Requires only 5 passive components for operation
Supports ultra-low power transport mode, with a static current of 370nA in factory mode
Graphical interface configuration, one-click export configuration to the user’s MCU application
Under different output currents, the conversion efficiency can reach up to about 95%, which is very efficient!Common application scenarios include:
Wearable devices
Handheld entertainment devices
Portable medical devices
Rechargeable smart home sensors
Mice, keyboards, touchpads
Interactive entertainment devices such as motion-sensing games
Low-power sensors and other IoT devices
5. nPM1300: One Chip is Better Than Eight
nPM1300 makes it easier for users, hardware engineers do not need to write code, and software engineers do not need to read data sheets. It is ready to use right out of the box; you just need to set it up in the intuitive graphical GUI and export the overlay file, which can then be added to your SDK project for use.Compared to multiple independent power management chips, nPM1300 integrates almost all the functions of power management chips. It combines the functionalities of the following eight chips:
1 charging management chip
2 BUCK voltage reduction chips
2 load switch chips
1 power meter chip
1 watchdog chip
1 hardware reset chip
Conventional discrete chip designs require many passive components, leading to complex schematics, larger PCB areas, and higher BOM costs. The nPM1300 requires very simple peripheral circuits, needing only 5 passive components to operate.The official provides recommended layout schemes for two types of packages:https://nsscprodmedia.blob.core.windows.net/prod/software-and-other-downloads/reference-layouts/npm1300/qfn/npm1300-qeaa-reference-layout-1_1.ziphttps://nsscprodmedia.blob.core.windows.net/prod/software-and-other-downloads/reference-layouts/npm1300/wlcsp/npm1300-caaa-reference-layout-1_0.zipComparison of conventional discrete chip schematic designs with nPM1300:PCB size comparison design:It can be said that nPM1300 is truly one chip is better than eight!
6. Hands-On Experience with the nPM1300 Evaluation Kit
Let’s briefly use the nPM1300 evaluation kit. Since I do not have a usable lithium battery on hand, this experience will not involve charging, discharging, or power meter functionalities.First, download the accompanying host software: nRF-Connect-for-Desktop, which supports the three major platforms: Windows, Linux, and MacOS. The latest version is:nrfconnect-setup-4.4.1-x64.exe. After downloading, install it, which will also install the Jlink driver:After the installation, open the software, and you will see that this tool is a collection of commonly used host software for Nordic chips. Since we are evaluating a PMIC, we also need to install nPM PowerUP,If the installation fails, you can try a few more times or restart the computer.After installation, prepare two Type-C USB data cables, and connect the two USB interfaces of the board to the computer. You will see the LD4 indicator light breathing and flashing. If the USB PMIC interface is not connected, the LD4 indicator light will be in a fast flashing state.After connecting to the computer, the device manager will show two additional serial port numbers:On first use of this software, you need to update the firmware on the SoC on the board:Open the nPM PowerUP software to connect the board, and you can see the logs in the bottom console:
14:52:40.188 Device Connected SN:EE177EE0F1D0259B
14:52:40.189 Getting serialport options from persistent store EE177EE0F1D0259B.pc-nrfconnect-npm
14:52:40.190 Device Connected SN:null
14:53:45.467 Selected device with s/n EE177EE0F1D0259B
14:53:45.478 Opened port with options: {"path":"COM4","baudRate":115200}
14:53:45.575 Closed port: COM4
14:53:45.575 Device setup ready for device with s/n EE177EE0F1D0259B
14:53:45.581 Opened port with options: {"path":"COM4","baudRate":115200}
14:53:47.831 Reset cause: SWRESET
The graphical interface is shown in the figure below:The basic functions of each window are:
DASHBOARD: Overall configuration of the nPM1300 chip
CHARGER: Battery charging current and voltage configuration
REGULATORS: DC-DC converter and load switch configuration
GPIOS: Configuration of 5 GPIOs and 3 GPIOs
SYSTEM FEATURES: Configuration of system reset, timer, POR, input current, etc.
PROFILES: Battery model creation and loading
GRAPH: Real-time curves of battery voltage, current, and temperature
By adjusting the voltage with the slider or manually entering a number, you can freely adjust the output voltage value. Using a multimeter or oscilloscope to measure VOUT1 and VOUT2 voltage values will change with the set values. Since I do not have a usable lithium battery on hand, this evaluation did not assess the charging, discharging, or power statistics functionalities.Interested friends can connect a battery for testing and view real-time information such as battery voltage, current, and temperature in the software.The official also provides a power meter expansion board that accompanies this evaluation kit—nPM Fuel Gauge Board, which generates battery charge-discharge model data. According to the official introduction, under temperature changes from -20°C to +60°C within 12 hours, the software algorithm’s power meter accuracy error is within 3%.After completing the configuration of the chip, click on the left <span>Export Configuration</span>, export the current configuration, and choose between <span>overlay</span> and <span>json</span> file formats. The overlay file can be used in our MCU application. After adding this file to the project, it will be called in the Zephyr TWI driver.To execute the device tree overlay file, please click on “edit build configuration” in the nRF Connect for VS Code extension, and then use the “Add overlay” button under “Devicetree overlay” to add the overlay file.Ensure that <span>prj.conf</span><span> includes these configurations:</span>
In-depth analysis of Nordic’s new generation PMIC applications in low-power wireless IoT devices (Part 1)www.eeyxs.com/livebroadcast/index/playback.html?tid=842&cid=6471
In-depth analysis of Nordic’s new generation PMIC applications in low-power wireless IoT devices (Part 2)www.eeyxs.com/livebroadcast/index/playback.html?tid=842&cid=6472
nPM1300 and nRF54 series solutionswww.eeyxs.com/livebroadcast/index/playback.html?tid=842&cid=6473
Webinar on July 5, 2023, by Nordic’s power management product director Geir Kjosavikwww.youtube.com/watch?v=aN5umN5zV0E
9. Conclusion
This article introduces the features of the nPM1300 power management chip and provides a brief experience of the basic functionalities of the evaluation kit and the basic use of the graphical configuration interface. Throughout the process, it can be observed that this chip is very simple to use, requiring almost no reading of the data sheet or writing of code for application in projects. It should be noted that the nPM1300 cannot be used independently; it requires an MCU host for configuration and control via the I2C interface. The official recommended typical application is to use it in conjunction with the nRF52 and nRF53 series SoCs, but it can also be used with other non-Nordic chips.Overall, the high integration of the nPM1300 significantly reduces the workload for users, and its ultra-low power consumption and ultra-high efficiency are advantages of this chip, making it very suitable for low-power IoT devices that do not require high current.
