USB type-C controllers with internal protection boost operation safety
USB Type-C specifies reversible plug orientation and cable direction, which simplifies attaching and powering a wide range of devices. The Type-C connection also consolidates support for all USB features including 480 Mbps USB 2.0 and 10 Gbps USB 3.1 data exchange, power delivery from 5V/0.5A up to 20V/5.0A, managed active cables that extend connection distance, and alternate mode that allows guest protocols such as HDMI or DisplayPort to use the same cable. Making things simpler for users requires more complex interface electronics to setup each connection correctly. The 20V maximum bus voltage (VBUS) for power delivery demands extra protection for low-voltage circuitry.
ST’s controller ICs simplify choices for designers, with one device dedicated to controlling downstream-facing ports (DFP), and one that can handle either downstream-facing (DFP), upstream-facing (UFP), or dual-role (DRP) use. Both new ICs support Type-C cable-attachment and connector-orientation detection and can operate over a supply range of 3V to 22V with no external voltage regulator, saving component count and PCB area.
In an analogue CMOS process, these USB Type-C controllers combine low power consumption with robust, high-voltage capability. Over-voltage protection up to 22V for the CC lines and up to 28V for the high-voltage pins is also built-in, which prevents damage in the event of accidental short-circuit to VBUS. There is also on-chip discharge circuitry for the VBUS and VCONN power lines, which allows cables to be disconnected safely.
The STUSB4710 DFP controller targets power-source applications such as AC adapters and power supplies, power hubs, docking stations, smart plugs, and displays. The IC integrates all the circuitry needed to negotiate power delivery with connected devices, and can support up to five Power Delivery Profiles. Through its embedded Non-Volatile Memory, it is fully customizable and can handle the entire connection setup with no external CPU involvement; so it can be used directly without any extra software or firmware. In case of multi-port applications (4-port power hub, for instance), an I²C interface allows a parallel connection of multiple STUSB4710 ICs to a microcontroller (MCU) to implement power-sharing algorithms.
The STUSB1602 can manage USB Type-C ports in power sources or devices. On-chip Configuration-Channel (CC) control logic manages the entire connection setup including selecting the VBUS default, medium-current, or high-current mode. The device integrates a protected and programmable 600 mA VCONN power switch to support accessories and active cables. The STUSB1602 also implements a USB PD physical layer (including a Bi-phase Mark Coding IP) to support power-delivery software stack implemented by an external MCU. The hardware and the software is USB PD 2.0 certified both as a Sink and a Source. It is compatible with USB PD 3.0 core features and most options. The STUSB1602 supports accessory modes and dead-battery mode.
Prices are from $0.75 for the STUSB1602 to $0.80 for the STUSB4710, in 4 x 4 mm QFN24 package, all (1000). The STUSB1602 evaluation board (P-NUCLEO-USB002) includes an STM32F0 microcontroller and a type-C cable and is $48.90. The STUSB4710 evaluation board (STEVAL-ISC003V1) embeds a DC/DC converter and is available for $50.