USB5744
DS00001855E-page 6
2015-2017 Microchip Technology Inc.
2.0
INTRODUCTION
2.1
General Description
The Microchip USB5744 hub is low-power, OEM configurable, USB 3.1 Gen 1 hub feature controller with 4 downstream
ports and advanced features for embedded USB applications. The USB5744 is fully compliant with the
Universal Serial
Bus Revision 3.1 Specification
and
USB 2.0 Link Power Management Addendum
. The USB5744 supports 5 Gbps
SuperSpeed (SS), 480 Mbps Hi-Speed (HS), 12 Mbps Full-Speed (FS), and 1.5 Mbps Low-Speed (LS) USB down-
stream devices on all enabled downstream ports.
The USB5744 supports the legacy USB speeds (HS/FS/LS) through a dedicated USB 2.0 hub feature controller that is
the culmination of five generations of Microchip hub feature controller design and experience with proven reliability,
interoperability, and device compatibility. The SuperSpeed hub feature controller operates in parallel with the USB 2.0
controller, decoupling the 5 Gbps SS data transfers from bottlenecks due to the slower USB 2.0 traffic.
The USB5744 supports downstream battery charging. The USB5744 integrated battery charger detection circuitry sup-
ports the USB-IF Battery Charging (BC1.2) detection method and most Apple devices. The USB5744 provides the bat-
tery charging handshake and supports the following USB-IF BC1.2 charging profiles:
• DCP: Dedicated Charging Port (Power brick with no data)
• CDP: Charging Downstream Port (1.5A with data)
• SDP: Standard Downstream Port (0.5A with data)
• Custom profiles loaded via SMBus or OTP
Additionally, the USB5744 includes many powerful and unique features such as:
PortSwap
, which adds per-port programmability to USB differential-pair pin locations. PortSwap allows direct alignment
of USB signals (D+/D-) to connectors to avoid uneven trace length or crossing of the USB differential signals on the
PCB.
PHYBoost
, which provides programmable levels of Hi-Speed USB signal drive strength
in the downstream port transceivers. PHYBoost attempts to restore USB signal integrity
in a compromised system environment. The graphic on the right shows an example of
Hi-Speed USB eye diagrams before and after PHYBoost signal integrity restoration. in
a compromised system environment
VariSense
, which controls the USB receiver sensitivity enabling programmable levels of USB signal receive sensitivity.
This capability allows operation in a sub-optimal system environment, such as when a captive USB cable is used.
The USB5744 can be configured for operation through internal default settings. Custom OEM configurations are sup-
ported through external SPI ROM or OTP ROM. All port control signal pins are under firmware control in order to allow
for maximum operational flexibility, and are available as GPIOs for customer specific use.
The USB5744 is available in commercial (0°C to +70°C) and industrial (-40°C to +85°C) temperature ranges. An internal
block diagram of the USB5744 is shown in
