New Power Devices Push TI to Forefront as only Vendor with
Complete Universal Serial Bus Hub Solution
Four-Port Hub Controller and Transient Suppressor Add Breadth
to USB Offering
DALLAS (Feb.10, 1997) -- With two new power management devices
for Universal Serial Bus (USB) from Texas Instruments (TI), designers
can protect personal computers (PCs) and peripheral equipment
from electrical damage caused by electrical surges, short circuits
and over-current and over-temperature conditions. These power
management devices complement an already extensive USB product
line and give TI the most comprehensive USB product offering in
the industry.
Because a PC user plugs a wide variety of low- to medium-speed
peripheral devices into any USB port, power management and protection
against accidental electrical damage are critical to assuring
equipment reliability.
In addition to these power management devices (TPS2014 and TPS2015),
TI also announced that samples of a four-port USB hub controller
(TUSB2140) with Inter-Integrated Circuit (I2C) bus circuitry is
scheduled to be available late in the first quarter of 1997.
The TUSB2140 can be used in a PC monitor to allow USB to control
operating characteristics like brightness, contrast, and vertical
and horizontal hold.
"These new power devices, along with the four-port hub controller,
continue to fill out our USB product line, making TI the only
company in the industry to offer all of the components a designer
needs to implement a USB hub solution," said Paul Thomas,
TI's manager of strategic marketing for USB. "Most downstream
USB hubs will be embedded in PC peripheral equipment ranging from
monitors and printers to keyboards and other peripherals centrally
located on the desktop. Our long-term USB plans call for more
USB devices that bring additional value to system designers in
terms of greater functionality and cost-effectiveness."
USB Power Management Devices
The TPS2014 and TPS2015 are USB-specific power switches that provide
maintenance-free protection against electrical damage and high
temperatures, increasing system reliability and reducing repair
costs of PCs and peripheral equipment. When the TPS2014/15 devices
detect an over-current condition, they will automatically limit
the current to a specified safe level. The host, peripheral or
hub controller uses the fault signal on the TPS2014/15 to monitor
the system voltage bus and provide feedback to the system interface
where the user is notified of the condition. Both the TPS2014
and TPS2015 power distribution switches have an integrated 95-ohm
MOSFET power switch, which meets the USB limitations for voltage
drop and regulation.
Excessive current draw through the TPS2014/15 may generate an
over-temperature condition with the devices. The TPS2014/15 can
detect an over-temperature condition and shut down the flow of
power through the devices to prevent damage. Additionally, the
power switches have an under-voltage lock-out (UVLO) feature that
keeps power from being distributed if the power supply drops below
4V, assuring downstream peripheral equipment will be properly
powered at all times. The UVLO feature also ensures that the
TPS2014/15 will be in the "off" state when powered up.
By combining short circuit, thermal protection, and UVLO in one
chip, the TPS2014/15 power switches eliminate the need for additional
fuses or other protection devices, reducing the component count
in the system. Unlike certain kinds of fuses, like Polyfuses,
now being considered for use in USB systems, the TPS2014/15 meet
all requirements of the USB specification for a current management
device.In addition to short circuits and overheating conditions,
PCs with USB can experience electrostatic discharge (ESD) as peripherals
are plugged into or unplugged from USB ports. Another newly introduced
USB power device is the SN75240, a dual-port electrical transient
suppressor. This device complements the TPS2014/15 power management
devices and increases the tolerance to noise transients that may
be induced on the USB signal lines.
Pricing and Availability
For testing purposes, evaluation modules (EVM) for the previously
disclosed TUSB2040/70 hub controller devices are available from
TI and its authorized distributors at a suggested resale cost
of $349 for the TUSB2040 EVM and $399 for the TUSB2070 EVM.
A separate EVM for the TPS2014/15 is also available from TI and
its authorized distributors free of charge.
The TPS2014/15 and SN75240 are fabricated using TI's advanced
LinBiCMOS process. The TPS2014/15 come in eight-pin small outline
in-line circuit (SOIC) and dual in-line packages (DIPs), while
the SN75240 are packaged in thin shrink small outline packages
(TSSOP). These devices are available now from Texas Instruments
and its authorized distributors. Suggested resale pricing in
quantities of 1,000 for the TPS2014/15 is $0.97 and $0.44 for
the SN75240.
Samples of the TUSB2140 four-port hub controller with I2C control
circuitry are expected to be available later in the first quarter
of 1997 from TI and its authorized distributors. Suggested resale
pricing in quantities of 1,000 is anticipated to be $3.89.
