•

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 UC5601 provides precision resistive pull-up to a 2.9V reference for all

18 lines in a Small Computer Systems Interface (SCSI) bus cable. The

SCSI-2 standard recommends active termination at both ends of every ca-

ble segment utilizing single ended drivers and receivers.

Internal circuit trimming is utilized, first to reduce resistor tolerances to

±3%

and then to adjust the regulator’s output voltage to insure termination cur-

rent accuracy of

±3%.

The UC5601 provides a disconnect feature which, upon a logic command,

disconnects all terminating resistors, and turns off the regulator; greatly re-

ducing standby power.

Other features include negative clamping on all signal lines, 20mA of active

negation sink current capability, regulator current limiting, and thermal shut-

down protection.

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.

UC5601

SCSI Active Terminator

FEATURES

DESCRIPTION

BLOCK DIAGRAM

Circuit Design Patented

10/94

UDG-94060