SILICONIX, represented in Australia by Braemac , has released small computer systems interface (SCSI) bus terminators for SCSI bus operational modes from SCSI-1 to SPI-4 (Ultra 320).
They are built on Vishay's high-voltage 0.8-micron BiCMOS process. They are pin and function-compatible, lead-free replacements for the industry-standard UCC56xx series of SCSI terminators.
The new SiP56xx SCSI terminator family is intended for use in 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 SiP5630 and SiP5670 are nine-line multi-mode terminators, the SiP5628 and SiP5668 are 14-line terminators, and the SiP5638 and SiP5678 are 15-line terminators.
Each of the 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 minimise 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.
The nine-line SiP5630 and SiP5670 have a 2.7-V to 5.25-V TERMPWR range for all S/E and LVD specifications. Both provide a master/slave input and status indicator pins. They are available in a lead-free, thermally-enhanced QSOP-36 package.
The SiP5628 and SiP5668 14-line terminators and SiP5638 and SiP5678 15-line terminators all are available in a thermally-enhanced, lead-free SQFP-48 package. The 14-line SiP5628 and SiP5668 terminators serve as an alternate source to the UCC5628, while the 15-line SiP5638 and SiP5678 provide designers with an alternate source to TI's UCC5638. Both 14-line terminators also feature status indicator pins.
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, 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 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 have 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.
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 a temperature range of 0°C to 70°C.