Texas Instruments UC5609DWPTR, UC5609DWP Datasheet

• Reverse Disconnect

• Complies with SCSI, SCSI-2 and SPI-2

Standards

• 6pF Channel Capacitance during
Disconnect

• 100µA Supply Current in Disconnect
Mode

• Meets SCSI Hot Plugging Capability

•−650mA Sourcing Current for

Termination

• +200mA Sinking Current for Active
Negation

• Provides Active Termination for 18 Lines

• Logic Command Disconnects all

Termination Lines

• Trimmed Termination Current to 5%

• Trimmed Impedance to 5%

• Current Limit and Thermal Shutdown

Protection

The UC5609 provi des 18 lines of active termination for a SCSI (Small
Computer Sy s t em s I nt er f ac e ) par all el bus. The SCS I s tandard recom­mends active termination at both ends of the bus cable.

The UC5609 is pin-for-pin compatible with its predecessors, the
UC5601, UC 5602 and UC5608 - 18 Lin e Active Terminators, except
for the r everse disconnect sense. Parametrica lly the UC5609 has a
5% tolerance on impedan ce and curre nt compared to a 3% tolerance
on the UC56 01 and the si nk current i s increased from 20 to 200mA.
The low sid e clamps have been re moved. Custom power pac kages
are utilized to allow normal operation at full power conditions (2
Watts).

When in disconnect mode the terminator will disconnect all terminat­ing resistors and disable the regulator, greatly reducing standby
power. The output channels remain high impedance even without
Termpwr applied.

Internal circuit trimming is utilized to tri m the impedance to a 5% toler­ance and, most importantly, to trim the outp ut current to a 5% toler­ance, as c lose to the max SCSI spec as possible, which maximizes
noise margin in fast SCSI operation.

Other feat ures include 4.0 to 5.25V Termpwr, thermal shutdown and
current limit.

This device is offered in low the rmal re sistance v ersions of the indus­try standard 28 pin wide body SOIC, 28 pin wide body TSSOP, and 28
pin PLCC, as well as 24 pin DIP.

UC5609

18-Line Low Capacitance SCSI Active Terminator

FEATURES DESCRIPTION

BLOCK DIAGRAM

Circuit Design Patented

4/97

UDG-94126

* PWP package pin 23 serves as signal ground; pins 7, 8, 9,
20, 21 and 22 serve as heats in k/ gro un d.

TSSOP-28 (To p View)
PWP Package

ABSOLUTE MAXIMUM RATINGS

Termpwr Vo ltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7V

Signal Line Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to +7V

Regulator Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1A

Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to +150°C

Operating Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −55°C to +150°C

Lead Temperature (Soldering, 10 Sec.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300°C

RECOMMENDED OPERATING CONDITIONS

Termpwr Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8V to 5.25V

Signal Line Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to +5V

Disconnect Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to Termpwr

Unless otherwise specified all voltages are with respect to Ground. Currents are posi­tive into, negative out of the specified terminal.
Consult Packaging Section of Unitrode Integrated Circuits databook for thermal limita­tions and consid era ti on s of pac ka ges.

UC5609

CONNECTION DIAGRAMS

PLCC-28 (Top View)
QP Package

* QP package pins 12 - 18 serve as both heatsink and signal
ground.

* DWP package pin 28 serves as signal ground; pins 7, 8, 9,
20, 21, 22 serve as heatsink/ground.

SOIC-28 (Top View)
DWP Package

Note: Drawings are not to scale.

DIL-24 (Top View)
N or J Package

2