SN75LBC968, the industry's first nine-channel SCSI transceiver integrated with active termination, can solve the noise problems associated with high-speed single-ended parallel data buses.
As the designs of SCSI (Small Computer System Interface) bus systems have increased in speed, (up to 10 million transfers per second) data corruption due to noise has increased. The 'LBC968 provides more accurate and reliable data communication in these high-performance systems.
The 'LBC968 transceiver/terminator presents a low capacitance of only 13.5 pF, which is much less than the SCSI specification's limit of 25 pF per node on the bus. High node capacitance decreases the signal amplitude and increases the chance of data errors on the SCSI bus. In addition, the driver outputs of the 'LBC968 have active signal negation which improves the signal to noise ratio on heavily loaded buses.
The 'LBC968 also limits the slew-rate, minimizing the possibility of cross-talk interference to adjacent lines. The accurate threshold levels and wider voltage hysteresis on the receivers of the 'LBC968 give stable noise margins and a 5 ns pulse noise rejection filter on the receiver provides additional selectivity between noise and valid data.
The 'LBC968 offers an effective bridge between 3.3 volt logic to the 5 volt SCSI bus, providing an effective migration path for upgrading a computer system to low-voltage logic while using SCSI as the I/O subsystem. An integrated current-mode terminator provides the highest level of current to the bus allowed by the specification, improving signal integrity. The 'LBC968 also includes a common enable for the active terminator.
The SN75LBC968 supports the fast SCSI standard of 10 million data transfers per second. The device consists of nine identical channels and conforms to the requirements of the SCSI-2 and proposed SCSI-3 specifications.
The SN75LBC968 is packaged in the space-saving 56-pin shrink-small-outline package (SSOP).
For increased bus data reliability and performance up to 25 meters, we offer the SN75LBC976 Differential SCSI Nine-Channel Transceiver.
Vol 10, Fall 1994