IMP5121

The IMP5121 Plug and Play terminator represents next-generation technology for SCSI termination applications. The low-voltage BiCMOS architecture  mployed in its design offers performance superior to older passive and active techniques. IMP's architecture employs high-speed adaptive elements for each channel, providing the fastest response possible. The channel bandwidth is typically 35MHz. The IMP5121 compares favorably to older linear regulator pproaches whose bandwidth's are dominated by the output compensation capacitor and are limited to the 500KHz bandwidth region (see further discussion in the Functional Description section). IMP's architecture also eliminates the output compensation capacitor required in earlier terminator designs. Each is approved for use with SCSI-1, -2, -3, ULTRA and beyond - providing the highest performance alternative available today.

Another key improvement of the IMP5121 products lies in their ability to insure reliable, error free communications even in systems which do not necessarily 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 these problems. The IMP5121 architecture is much more tolerant of marginal system integrations.

Recognizing the needs of portable and configurable peripherals, the IMP5121 has a TTL compatible sleep/disable mode. Quiescent current is typically less than 375mA in this mode, while the output capacitance is less than 3pF.

Reduced component count is also inherent in the IMP5121 architecture. Traditional termination techniques require large stabilization and transient protection capacitors of up to 20mF in value and size. The IMP5121 architecture does not require these components, allowing all the cost savings associated with nventory, board space, assembly, reliability, and component costs.

The IMP5121 has multiple disables for full Plug and Play SCSI capability for Host Bus Adapters with 3 SCSI connectors. It also splits the upper 9 termination lines for mixing 16-bit (wide) and 8-bit (narrow) buses with minimal board trace capacitance.