USB Power Delivery (USB PD) is a fast-charging technology that enables devices to deliver and receive power over a USB connection. It is part of the USB standard and is intended to make USB more versatile for charging and powering a wide range of electronic devices, including smartphones and tablets.
While USB PD as a concept was originally introduced in 2012, capable of delivering up to 100 W of power, it has evolved in tandem with the widespread adoption of the USB-C interface and is regularly reviewed and updated as power and charging requirements increase. The latest version (USB PD 3.2) now supports up to 240 W of power to enable fast charging of power hungry laptops and monitors (Figure 1). The growing number of devices using this charging technology means it is becoming increasingly common for charging adapters to feature two (or more) USB Type-C charging ports. A key component in the design of these charging ports is the USB Type-C and power delivery controller – an integrated circuit (IC) that manages the communication, configuration, and electrical negotiation between devices using a USB-C connection. Nexperia recently introduced two new USB Type-C and power delivery controller ICs, making it the first semiconductor manufacturer to offer a turn-key solution for this charging technology. This blog reviews how these controllers employ dynamic power distribution to enable smarter multi-port charger designs than alternative power delivery solutions offered by other semiconductor manufacturers.
Designing a 120 W two-port wall charger
For an engineer designing a dual-port 120 W (total) wall charger, a seemingly obvious choice might be to select an integrated two-channel power delivery controller capable of managing the simultaneous delivery of up to 60 W from each port. However, while this approach certainly meets the original design specification for a 120 W wall charger, it has an inherent limitation – it is limited to providing up to 60 W per port, meaning that higher power devices (>60 W) will be provided with less current than they can handle meaning they would charge more slowly, even if the second port is left unused. Clearly, the engineer has the option to increase the power output, for example up to 100 W for a single connection, but balance between the 2 ports when both channels are connected.
Nexperia’s smart power delivery controllers offer a more flexible charging solution
A superior approach would be to use Nexperia’s NEX52041(up to 100 W) or NEX52080 (up to 140 W) USB Type-C and Power Delivery controller ICs. These single channel controllers feature an integrated microcontroller unit (MCU) to support multi-IC communication for smart power delivery in multi-port applications. This means that in the 120 W wall charger design considered previously, two of these controller ICs can dynamically adjust the power delivered from each port in response to the charging requirements of connected devices. So, for example, if a laptop connected to one port required 100 W, the two controllers can communicate to dynamically allow 100 W of power to be delivered to this port, while simultaneously restricting the maximum power output of the second port to only 15 W, meaning the maximum output power never exceeds 120 W.
NEX52041 and NEX52080 are flexible, robust and space-efficient
The NEX52041, and NEX52080 with extended power range (EPR), offer excellent compatibility with different charging protocols to ensure USB ports have the capability to charge phones, laptops, and other tools from various equipment manufacturers. Apart from USB Type-C with PD, these controllers also support multiple DP/DM based fast charging protocols for enhanced compatibility with recent and legacy devices. The NEX52041 and NEX52080 are designed with a constant-voltage (CV), constant-current (CC) control loop to support applications using an optocoupler and provide interoperability with different DC/DC or AC/DC converters. The embedded MCU in these controllers providing the flexibility to design and update customized features while also enabling software or firmware updates required to ensure chargers continue to comply with changing USB standards. Unlike similar competing devices, which rely on additional external components to provide adequate protection, the NEX52041 and NEX52080 include internal protection features which provide up to 30 V of overvoltage tolerance on the VBUS/CC/DP/DM pins. This ensures robust performance while also lowering the bill of materials (BOM) by minimizing the requirement to use external components.
These controllers are available in 4 x 4 QFN-16 and QFN-24 packages (Table 1) whose pinout provides adequate programmable GPIOs and I2C interfaces to support multi-IC communication for smart power distribution in multi-port charger applications.
Nexperia becomes the first manufacturer to offer a turn-key USB Type-C with PD solution
For ultimate convenience, engineers can now conveniently combine these controllers ICs with Nexperia’s AC/DC Buck-boost controller, MOSFET, GaN and TVS/ESD products to quickly implement a turnkey solution for use in various power adapter applications (Figure 3).
