•

Complies with SCSI, SCSI-2

Standards

•

10pF Channel Capacitance During

Disconnect

•

Active Termination for 18 Lines

•

Logic Command Disconnects all

Termination Lines

•

Low Supply Current in Disconnect

Mode

•

Trimmed Regulator for Accurate

Termination Current

•

Current Limit and Thermal

Shutdown Protection

•

110 Ohm Termination

•

Meets SCSI Hot Plugging

The UC5602 is a pin compatible version of its predecessor, the UC5601,

and is targeted for high volume applications which require active termina-

tion, but not the high performance of the UC5601. The major differences

are relaxed output current and termination tolerances, and the absence of

low side clamps.

The UC5602 provides 18 lines of active termination for a SCSI (Small

Computer Systems Interface) parallel bus. The SCSI-2 standard recom-

mends active termination at both ends of the cable segment, and SCSI-3

will make it a requirement.

The UC5602 provides a disconnect feature which, when opened or driven

high, will disconnect all terminating resistors, and disables the regulator;

greatly reducing standby power. The output channels remain high imped-

ance even without Termpwr applied.

Internal circuit trimming is utilized, first to trim the impedance to a 7% toler-

ance; and then most importantly, to trim the output current 7% tolerance,

as close to the max SCSI as possible, which maximizes noise margin in

fast SCSI operation.

Other features include thermal shutdown, current limit, and 40mA of active

negation sink current capability.

This device is offered in low thermal resistance versions of the industry

standard 28 pin wide body SOIC and PLCC, as well as a 24 pin DIL plastic

package.

UC5602

SCSI Active Terminator

FEATURES

DESCRIPTION

BLOCK DIAGRAM

Circuit Design Patented

10/94

UDG-94052