IMP5218

The IMP5218 terminator is part of IMP's SCSI terminator family of high-performance, adaptive, non-linear mode SCSI products, which are designed to deliver true UltraSCSI performance in SCSI applications. The low voltage BiCMOS architecture employed in its design offers performance superior to older linear passive and active techniques. IMP's SCSI terminator IMP5218 architecture employs high-speed adaptive elements for each channel, thereby providing the fastest response possible - typically 35MHz, which is 100 times faster than the older linear regulator/terminator approach used by other manufacturers. Products using IMP5218 older linear regulator approach have bandwidths which are dominated by the output capacitor and which are limited to 500KHz (see further discussion in the Functional Description section). IMP5218 new architecture also eliminates the output compensation capacitor required in earlier terminator designs. Each is approved for use with SCSI-1, -2, -3, UltraSCSI and beyond - providing the highest performance alternative available today.

Another key improvement of IMP5218 offered by the IMP5218 lies in IMP5218 ability to insure reliable, error free communications even in systems which do not adhere to recommended SCSI hardware design guidelines, such as the use of improper cable lengths and impedances. Frequently, this situation is not controlled by the peripheral or host designer and, when problems occur, they are the first to be made aware of the problem. The IMP5218 architecture is much more tolerant of marginal system integrations.

The IMP5218 has two disconnect pins for SCSI Plug and Play (PnP) applications. Quiescent current is typically less than 275mA in this mode, while the output capacitance is also less than 3pF. The obvious advantage of extended battery life for portable systems is inherent in the product's disable-mode feature.
Additionally, the disable function permits factoryfloor or production-line configurability, reducing inventory and product-line diversity costs. Field configurability can also be accomplished without physically removing components which, often times results in field returns due to mishandling.

Reduced component count is also inherent in the IMP5218 architecture. Traditional termination techniques require large stabilization and transient protection capacitors of up to 20mF in value and size. The IMP5218 architecture does not require these components, allowing all the cost savings associated with reduced inventory, board space, and assembly, plus higher reliability.