1999-05-24 , S/IC-2067/34
Product News From Philips Semiconductors

Third generation USB hub technology offers low cost implementation

Philips Semiconductors, a leading developer of Universal Serial Bus (USB) solutions, today announced the availability of its third generation USB hub technology, the  ISP1122. As part of the ISP112x family, the ISP1122 marks Philips Semiconductors' entrance into the USB stand-alone hub market. Building on the success of the previous two generations, Philips Semiconductors offers a more highly integrated, lower cost solution with its first family of USB hub ICs specifically targeted for stand-alone operation in the PC Peripheral and Motherboard markets. Philips Semiconductors' newest USB solution will be showcased at Computex in Taiwan, 1 June 1999.

Philips Semiconductors established itself as a forerunner of the USB market with the introduction of the industry's first USB hub, the PDIUSBH11. Its successor, the  PDIUSBH11A is considered today's reference for interoperability performance. With the announcement of its third generation technology, Philips Semiconductors has continued to expand upon the hub family, offering feature enhancements and cost optimization. As a USB hub implementation, the ISP112x family provides developers a very low cost bill of materials (BOM). "At low total cost, few external components and proven USB 1.1 compliance, ISP1122 allowed us to focus on our own technology, rather than on how to implement a USB hub," said Peretz Tzarnotzky, vice president, engineering, Computer Access Technology Corporation (CATC). "The design risk and engineering effort were negligible."

The ISP1122 is a high performance, stand-alone USB hub device with integrated hub repeater, hub controller, Serial Interface Engine (SIE), transceivers and a 3.3 V voltage regulator. Designed for interoperability across a wide range of peripherals and systems and compliant with the latest USB Specification Revision 1.1, the ISP1122 has a configurable number of downstream ports, ranging from 2 to 5 and can be used in self-powered, bus-powered or hybrid-powered modes. Additional features include integrated overcurrent detection and port power control, easy visual monitoring of USB traffic via the GoodLink™ indicator outputs, a serial I²C^®-bus interface for external Electrically Erasable Programmable Read Only Memory (EEPROM) access and a reduced frequency (6 MHz) crystal oscillator. These features allow significant cost savings in system design and easy implementation of advanced USB functionality into PC peripherals.

Both overcurrent detection logic and power switching logic are integrated on-chip in the Philips Semiconductors' USB solution, as opposed to external, as is the case with competitors' solutions. This integration of the ISP1122 eliminates external circuitry, reduces the number of necessary components and verifies design robustness - creating a lower cost solution. With the implementation of overcurrent detection and power switching, only standard components are needed externally, offering designers a variety of supplier options thereby further reducing the cost.

Additionally, Philips Semiconductors' ISP1122 conforms to the USB 1.1 maximum Suspend Current specification (<500µA) in actual applications. This is especially important in bus-powered applications, such as hub boxes, port replicators and some compound devices - all primary applications for USB.

Samples of the ISP1122 and the ISP1121 are available now from Philips Semiconductors.

Philips Semiconductors, a division of Royal Philips Electronics, headquartered in Eindhoven, The Netherlands, is the eighth largest semiconductor supplier in the world. Philips Semiconductors' innovations in digital audio, video, and mobile technology position the company as a leader in the consumer, multimedia and wireless communications markets. Sales offices are located in all major markets around the world and are supported by systems labs. Additional information on Philips Semiconductors can be obtained by accessing its home page at http://www.semiconductors.philips.com