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.