FEATURES

• Auto Selection Single Ended (SE) or

Low Voltage Differential (LVD)

Termination

• Meets SCSI-1, SCSI-2, Ultra2 (SPI-2

LVD SCSI), Ultra3, Ultra160 (SPI-3)

and Ultra320 (SPI-4) Standards

• 2.7V to 5.25V Operation

• Differential Failsafe Bias

• Thermal packaging for low junction

temperature and better MTBF.

DESCRIPTION

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 0°C to 70°C.