USB3803 Standard Microsystems Corp., USB3803 Datasheet - Page 3

• Manufacturer Part Number: USB3803
• Description: Usb 2.0 High-speed Hub Controller Optimized For Portable Applications
• Manufacturer: Standard Microsystems Corp.

USB 2.0 High-Speed Hub Controller Optimized for Portable Applications
General Description
SMSC USB3803C
The SMSC USB3803 is a low-power, USB 2.0 hub controller with three downstream ports. The
USB3803 can attach to an upstream port as a full-speed hub or as a full-/hi-speed hub and supports
low-speed, full-speed, and hi-speed (if operating as a hi-speed hub) downstream devices on all of the
enabled downstream ports.
The USB3803 has been specifically optimized for mobile embedded applications. The pin-count has
been reduced by optimizing the USB3803 for mobile battery-powered embedded systems where power
consumption, small package size, minimal BOM, and battery charger detection capabilities are critical
design requirements. Standby mode and Bypass mode power has been minimized. Instead of a
dedicated crystal, reference clock inputs are aligned to mobile applications. Flexible integrated power
regulators ease integration into battery powered devices. Automatic battery charger detection is
available on the upstream port. All required resistors on the USB ports are integrated into the hub.
This includes all series termination resistors on D+ and D– pins and all required pull-down and pull-up
resistors on D+ and D– pins.
The integrated USB switch allows USB3803 to bypass the USB Hub and directly connect the upstream
and Port 3 downstream USB port for operational modes that do not require Hi-Speed media transfers.
The bypass switch enables multiple connectivity options to the USB port while preserving the high
speed signal quality in USB Hub Mode.
The USB3803 integrated battery charger detection circuitry supports USB-IF 1.1 charger detection
methods. These circuits are used to detect the attachment and type of a USB Charger and provide an
interrupt output to the portable device indicating that charger information is available to be read from
USB3803 status registers via the serial interface.
The USB3803 includes programmable features such as:
MultiTRAK
consistent full-speed data throughput regardless of the number of active downstream connections.
MultiTRAK
PortMap which provides flexible port mapping and disable sequences. The downstream ports of a
USB3803 hub can be reordered or disabled in any sequence to support multiple platform designs with
minimum effort. For any port that is disabled, the USB3803 hub controllers automatically reorder the
remaining ports to match the USB host controller’s port numbering scheme.
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 upstream and 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.
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.
TM
TM
outperforms conventional USB 2.0 hubs with a single TT in USB full-speed data transfers.
Technology which utilizes a dedicated Transaction Translator (TT) per port to maintain
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Revision 1.0 (07-05-11)