Sep 21 2009

Pericom – USB Charging and USB 3.0

Published by at 1:53 am under Uncategorized

With low power being a driving force for system design today, the addition of sleep and power down modes has complicated the functionality of traditional USB ports.  In addition to data transfer and functional communication, the USB connection is also used to provide power and charging functions to portable peripherals.  To date, devices can only charge through the USB port when the operating system is awake, and the source device  (desktop, notebook, netbook) is awake and in full functioning mode.

Pericom Semiconductor is introducing the PI5USB56 IC to add charging capability to devices that are in power down and sleep mode.  Like other parts on the market, the USB switch is USB 3./2.0 High speed complaint as well as USB 1.1 and 1.0 compliant.  However, the Pericom part works without software intervention so it is operating system and CPU independent.  This independence allows the device to charge Apple and RIM devices while the USB host is in standby mode.

The independence from software for the IC’s operation, allows it work in Notebooks, Netbooks, other line cord operated CE equipment with USB ports (TV, receivers, set top boxes, etc).  The independence from the CPU also allows the part to work in “non-hosted” smart charger that are now being designed for wall plug-in and automotive applications.

Shifting focus from power savings to high data rates, Pericom is introducing new ICs for the 5GB/s bi-directional packetized data USB3.0 marketplace.  The new USB ecosystem typical configuration is shown in figure 1. SuperSpeed-hr1

The high data rate has put some constraints on the cables used for the USB3.0 interface.  For extended distances and with multiple connections on the line, most applications benefit from using a signal ReDriver.  They are introducing two signal conditioners, now with adaptive equalization and auto-power down that will support up to 6meters of cable at full data rate.  These drivers are being installed at the host side, some peripheral side applications and also in active cable applications.

For use in data critical applications at full data rate, they are introducing a low jitter clock generator.  The clock generator exceeds the 3.1ps rms phase jitter specification with a 2.2ps phase jitter figure.  This part is targeted at such critical functions as USB3 to SATA interface controllers operating over an industrial temperature range.

For host controller and main system board applications, they have introduced a USB 3.0 Mux/Dumux switch.  Unlike a hub, this IC allows for MUXing multiple signals and USB3.0 ports to a single set of pins, with approx 200ps latency versus microsecond latency.  The part also supports low power functionality at 200uA max current.

All of these parts are currently sampling and will be in production shipments in Q4 ‘09.


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