Quick Tip #2: Power (Full) Options

Quick Tip #2: Power (Full) Options
The new Type-C connector can handle up to 100W of power to supply displays or charge larger devices like laptops, notebooks, or 2-in-1s (Figure 6). Additionally, power can flow in either direction, so your smartphone can charge your laptop (for short periods). The USB-IF BC1.2 (Battery Charge) specification covers previous USB charging schemes (see “How USB Charges Any Electronic Device” in this article). The new Type-C specification is covered in the Power Delivery 2.0 (PD) specification (see “Three Essential Technologies for Ultra-Mobile, Portable Embedded Systems”).
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Determining power requirements, selecting voltage, and choosing current delivery mechanisms under the PD specification is complex and based on USB-IF protocols (readers are encouraged to consult the aforementioned articles). Table 2 lists key power options in Type-C according to the PD specification.

Notably, observe how the new 100W (bidirectional) PD option coexists with the traditional BC1.2 specification. Designers must understand their system’s power delivery requirements and incorporate necessary charging, switching, and enumeration circuits. Beyond the latest PD specification, maximum USB power remains 15W (5V@3.0A), sufficient for all handheld mobile devices, portable hard drives, and USB accessories. Only laptops and displays (potentially not “embedded systems”) may require >50W .