Designing Next-Gen Chargers for Consumer Electronics

As rechargeable battery technology increases battery charge density and capacity, more and more consumer products are operating on Lithium-ion (Li-ion) battery power. Lower-power and higher-power products alike have transitioned to battery power, and both need higher-power battery chargers to meet market demand for faster charging. This trend applies to low-power mobile consumer electronic products such as tablet computers, smartwatches, and smartphones as well as higher-power consumer products such as robotic lawnmowers, e-bikes, and kitchen appliances. This is shown in the image below:

Lower-power and higher-power need faster charging, and standards are evolving to accommodate both. (Images: Littelfuse)

Higher-power charging for more products & faster charging

Industry standards organizations such as the USB-Implementers Forum and the Wireless Power Consortium have addressed the need for higher power chargers. The USB-Implementers Forum, for example, has enhanced its USB Type-C power delivery standard to accommodate up to 24 watts of charging power. The European Union is adopting this higher power standard and requiring all mobile phones, tablets, and cameras sold in its member countries to have a USB Type-C charging port by the end of 2024. This requirement will extend to laptop computers by spring 2026.

Designers of today's fast battery chargers face the challenge of safely distributing high charging power levels. Their products must be robust enough to withstand electrical hazards such as overcurrent, overvoltage, electrostatic discharge (ESD), and overtemperature conditions. Due to the high power consumption, designers must maximize their design's efficiency to minimize power loss.  

The designers of battery chargers need to understand the latest component options that will enable them to safeguard their next-generation designs of three types of battery charging systems from electrical hazards as well as components that can improve the efficiency of designs to minimize total power consumption.

USB-C chargers

USB ports are becoming ubiquitous on portable electronic devices. The USB-Implementers Forum has adapted the USB standard to enable more products to charge through a USB port. The USB Power Delivery Revision 3.1 specification is a significant update that enables the delivery of up to 240 watts of power over USB Type-C cables and connectors. The increase in power of the USB port requires a greater emphasis on safety and protection.

The image below shows an example of a typical USB-C multi-device charging system and block diagram along with the recommended components. The surrounding blocks identify components that can protect the USB-C charger and maximize its efficiency. The block diagram further details the charger circuitry, and the adjacent table indicates which circuits need the components. The diagram presents recommended component solutions to ensure a USB-C charger design's efficiency and protection from electrical hazards:

USB-C multi-device charging system, block diagram, and component recommendations.

Download the Design Reliable Chargers for NextGen Consumer Electronics whitepaper for more details about how to evaluate USB-C charger protection recommendations and maximize charging efficiency.

Lithium-ion battery chargers

A second type of charger is specifically designed for Lithium-ion batteries. This type of charger offers more design flexibility since power output is not limited by a standard. The image below provides recommendations:

Lithium-ion battery charging system, block diagram, and component recommendations.

Download the whitepaper to learn more about how to evaluate lithium-ion battery charger protection recommendations and maximize charging efficiency.

Wireless chargers

The third type of charger offers the convenience of eliminating the charger cable between the charger and the device requiring a charge. Wireless chargers defined by the Wireless Power Consortium can have a power level of up to 60W.  The benefits of wireless charging include eliminating the risk of damage to the charger or the load due to incorrect cable insertion or a damaged cable and less wear on charging port connectors. See diagram below:

Wireless charging system, block diagram, and component recommendations.

Download the whitepaper to learn more about how to evaluate wireless charging protection recommendations and maximize charging efficiency.

Applicable safety standards & compliant components

Multiple safety standards govern consumer products such as battery chargers. The table below contains the applicable national and international safety standards for battery chargers. Design teams must be aware of and understand the requirements for their products. See table below:

Worldwide charger safety standards and the Littelfuse components that enable compliance.

Recommended components for robust charger design

Ensuring the reliable performance of battery charging systems is essential as consumers rely on more battery-powered portable products. Protecting battery chargers from electrical hazards such as overcurrent, overvoltage, ESD, and overtemperature is critical for ensuring reliable operation. Design teams can save development time and costs by using component manufacturing expertise.

With the right components and applications engineering assistance, designers can optimize their design for rugged, reliable, and efficient performance. To learn more about emerging circuit protection, sensing, and power control technologies shaping the next generation of battery charging systems,

Download the Design Reliable Chargers for NextGen Consumer Electronics whitepaper to learn more about evaluating these protection recommendations and maximizing the charging system's efficiency, courtesy of Littelfuse. The whitepaper also introduces several unique Littelfuse components that can simplify the design challenge and contribute to more robust, reliable designs.