USBC and PD 31 Transform Charging Easing Battery Concerns

Imagine a world where your laptop, tablet, and even power tools all use the same charger with incredibly fast charging speeds. This is no longer science fiction but a reality being enabled by USB Type-C and USB Power Delivery (PD) technologies. USB Type-C, with its reversible plug orientation and robust data transfer capabilities, has become the industry standard. USB PD further extends USB-C's functionality by enabling higher power delivery for rapid charging across more devices.

The USB PD 3.0 specification already allowed for up to 100W of power (20V, 5A) in both directions, known as the Standard Power Range (SPR). The latest USB PD 3.1 specification expands this capability dramatically, increasing the power delivery limit to 240W (48V, 5A) through USB-C cables, designated as the Extended Power Range (EPR).

EPR mode enables power delivery up to 240W (48V, 5A). Like standard USB PD protocol negotiations, EPR mode requires receiving devices to evaluate and respond to new power capability messages. The selection of 48V as the maximum voltage primarily considers design safety margins.

Beyond the fixed voltage levels in EPR mode, power sources must also comply with Adjustable Voltage Supply (AVS) specifications. In EPR mode, AVS allows receiving devices to fine-tune voltages between 15V and 48V in 100mV increments, improving performance and thermal efficiency. AVS also enables devices to receive voltage from any charger, eliminating the need for custom adapters and creating consistent user experiences across electronic ecosystems.

While both Programmable Power Supply (PPS) and AVS feature programmable voltage steps, they serve different purposes. AVS functions as a constant voltage source, providing stable DC voltage to systems for improved efficiency. PPS offers smaller step increments (20mV) for direct battery charging, bypassing the device's battery charger. The key distinction is that PPS voltages change dynamically during charging, while AVS maintains constant voltage levels.

Portable battery-powered devices like Bluetooth speakers and power tools stand to benefit significantly from USB-C adoption. Implementing USB-C enables these devices to both charge through the USB-C port and power connected devices through the same interface. Products using single or multi-cell battery chargers can now pair with USB-C or USB PD controllers to receive and provide power through USB-C ports.

To simplify USB PD port design for battery-powered products, advanced USB PD controllers now incorporate I2C host support for direct battery charger control. This integrated approach enables dual-chip solutions without requiring external microcontrollers. The USB PD controller automatically updates the battery charger's parameters based on power negotiations through the USB PD port, eliminating the need for custom firmware development.

To support the full 240W Extended Power Range, reference designs pair USB PD controllers with bidirectional buck-boost charging controllers on single printed circuit boards. These complete solutions require no external microcontrollers or custom firmware, enabling true plug-and-play 240W bidirectional power delivery.

Such reference designs serve as integrated USB PD and charging solutions for products with 7-14 cell batteries, including power tools, vacuum cleaners, portable power stations, and e-bikes. The high level of integration reduces bill-of-materials costs, minimizes physical footprint, and significantly shortens time-to-market for new products.

With its expanded power capabilities, USB-C is establishing itself as the universal connector of the future. While implementing USB-C technology presents challenges, integrated solutions now exist that simplify both hardware and software aspects of design. Paired USB PD controllers and battery chargers, supported by comprehensive reference designs, enable smaller solution sizes and faster product development cycles across multiple industries.