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Siliconix unveils Pb-free replacements to UCC56xx SCSI terminators

Posted: 06 Jan 2005 ?? ?Print Version ?Bookmark and Share

Keywords:sip56xx? scsi? small computer systems interface? bus terminator? siliconix?

A new family of SCSI (small computer systems interface) bus terminators that provides flexible solutions for all SCSI bus operational modes from SCSI-1 to SPI-4 (Ultra 320) was announced by Siliconix Inc., an 80.4%-owned subsidiary of vishay intertechnology Inc.

Built on Vishay's high-voltage 0.8?m BiCMOS process, members of the SiP56xx SCSI terminator family serve as pin- and function-compatible, Pb-free replacements for the industry-standard UCC56xx series of SCSI terminators.

Target applications for the new terminator ICs include backplanes, host adapters, cabling in RAID disk arrays, storage area networks (SANs), network attached storage (NAS), servers and workstations, industrial computers, and high-end personal computers.

The six family members are the SiP5630 and SiP5670 9-line multi-mode terminators, the SiP5628 and SiP5668 14-line terminators, and the SiP5638 and SiP5678 15-line terminators. Each of the multi-mode terminators' output channels provides termination for one SCSI data signal, parity signal or control signal. The termination provides impedance matching of the SCSI bus to minimize signal reflections from the end of the bus, as well as the required SCSI bus biasing for either single-ended (S/E) or low voltage differential (LVD) operation.

Available in a Pb-free, thermally enhanced QSOP-36 package, both the SiP5630 and SiP5670 feature a 2.7V to 5.25V TERMPWR range for all S/E and LVD specifications, and provide a master/slave input and status indicator pins. Meanwhile, the SiP5628, SiP5668, SiP5638 and SiP5678 devices are available in a thermally enhanced Pb-free SQFP-48 package.

The SCSI bus terminators sense the operational state of the SCSI bus via the DIFFSENS bus signal and automatically switch to S/E or LVD operation as required, thereby allowing designers to order and implement a single device for newer LVD products and for the older SE devices that remain in use today. If a high-power differential (HPD) device is used with the SCSI bus, the terminator IC shifts into high impedance mode. The new terminators also present high impedance to the SCSI bus if the DISABLE pin is asserted or if the TERMPWR supply voltage is removed from the IC.

The SiP5668, SiP5670 and SiP5678 multi-mode terminators all feature an integrated SPI-3 delay filter. This on-chip mode-change delay enables designers to reduce the size and cost of external passive components for significant board space savings in SPI-3 designs.

Fusible link technology
To meet the termination resistance requirements of the SCSI standards, Vishay uses fusible link technology to trim the termination value. All six devices are rated for operation over the 0C to 70C temperature range.

Vishay Siliconix also plans to release a 27-line programmable terminator in a lead-free LQFP-80 package. By providing precise active termination for 27 LVD SCSI bus lines, the device will achieve peak bus performance, permitting the manufacture of more robust and reliable ULTRA320 and ULTRA640 systems. This programmable device will be suitable for backplanes that have a lower bus impedance in the 60? to 90? range.

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