Improved Speed and Package Replacement
for the SN75LBC976
Designed to Operate at up to 20 Million
Data Transfers per Second (Fast-20 SCSI)
Nine Differential Channels for the Data and
Control Paths of the Small Computer
Systems Interface (SCSI) and Intelligent
Peripheral Interface (IPI)
SN75976A Packaged in Shrink
Small-Outline Package with 25-Mil Terminal
Pitch (DL) and Thin Shrink Small-Outline
Package with 20-Mil Terminal Pitch (DGG)
SN55976A Packaged in a 56-Pin Ceramic
Flat Pack (WD)
Two Skew Limits Available
ESD Protection on Bus Terminals
Exceeds 12 kV
Low Disabled Supply Current 8 mA Typ
Thermal Shutdown Protection
Positive- and Negative-Current Limiting
Power-Up/Down Glitch Protection

description
The SN75976A is an improved replacement for
the industry’s first 9-channel RS-485
transceiver — the SN75LBC976. The A version
offers improved switching performance, a smaller
package, and higher ESD protection. The
SN75976A is offered in two versions. The ’976A2
skew limits of 4 ns for the differential drivers and
5 ns for the differential receivers complies with the
recommended skew budget of the Fast-20 SCSI
standard for data transfer rates up to 20 million
transfers per second. The ’976A1 supports the
Fast SCSI skew budget for 10 million
transfers per second. The skew limit ensures that the propagation delay times, not only from channel-to-channel
but from device-to-device, are closely matched for the tight skew budgets associated with high-speed parallel
data buses.
The patented thermal enhancements made to the 56-pin shrink small-outline package (SSOP) of the SN75976
have been applied to the new, thin shrink, small-outline package (TSSOP). The TSSOP package offers even
less board area requirements than the SSOP while reducing the package height to 1 mm. This provides more
board area and allows component mounting to both sides of the printed circuit boards for low-profile,
space-restricted applications such as small form-factor hard disk drives.