Texas Instruments UCC5638

Multimode SCSI 15 Line Terminator

The UCC5638 Multimode SCSI Terminator provides a smooth transition into the LVD SCSI Parallel Interface (SPI-2, SPI-3, SPI-4). It automatically senses the bus, via DIFFB, and switches the termination to either single ended (SE) or low voltage differential (LVD) SCSI, dependent on which type of devices are connected to the bus. The UCC5638 can not be used on a HVD, EIA485, differential SCSI bus. If the UCC5638 detects a HVD SCSI device, it switches to a high impedance state. The Multimode terminator contains all functions required to terminate and auto detect and switch modes for SPI-2, SPI-3 and SPI-4 bus architectures. Single Ended and Differential impedances and currents are trimmed for maximum effectiveness. Fail Safe biasing is provided to insure signal integrity. Device/Bus type detection circuitry is integrated into the terminator to provide automatic switching of termination between single ended and LVD SCSI and a high impedance for HVD SCSI. The multimode function provides all the performance analog functions necessary to implement SPI-2 termination in a single monolithic device. The UCC5638 is offered in a 48 pin LQFP package for a temperature range of 0C to 70C.