UCC5680

9LINE LVD ONLY SCSI TERMINATOR

WITH INTEGRATED SPI3 DELAYS

SLUS313D − MARCH 1999 - REVISED NOVEMBER 2003

1

www.ti.com

Ultra2 (Fast 40), Ultra3/Ultra160 (Fast 80)

and Ultra320 (Fast 160)

description

The UCC5680 is an LVD-only Small Computer System Interface (SCSI) terminator that integrates the mode

change delay function required by the SPI-3 specification. The device senses what types of SCSI drivers are

present on the bus via the voltage on the DIFFSENS SCSI control line. Single-ended (SE) and high-voltage

differential (HVD) SCSI drivers (EIA485) are not supported. If the chip detects the presence of an SE or HVD

SCSI driver, it disconnects itself by switching all terminating resistors off the bus and enters a high-impedance

state. The terminator can also be commanded to disconnect the terminating resistors with the DISCNCT input.

Impedance is trimmed for accuracy and maximum effectiveness. Bus lines are biased to a failsafe state to

ensure signal integrity.

The UCC5680 is offered in both 24-pin and 28-pin TSSOP (PW) packages for a temperature range of 0

°C to

70

°C.

functional block diagram

UDG−00067

11

12

15

100 ms

TO

300 ms

DELAY/

FILTER

DIFFB

2.15 V

0.6 V

DISCNCT

10

µA

HIGH−VOLTAGE

DIFFERENTIAL

LOW−VOLTAGE

DIFFERENTIAL

SINGLE−ENDED

REF

1.3V

−15 mA

≤ I

50

µA ≤ I

4

52

52

3

124

56 mV

56 mV

+ −

− +

25

26

L1 −

L1+

L9 −

L9+

REF

1.25V

1

REG

28

TRMPWR

14

GND

DIFSENS

52

52

124

56 mV

56 mV

+ −

− +

27

SE

LVD

HVD

DISCNCT

OPEN

DOWN

OPEN

OPEN

MODE

ALL SWITCHES

ENABLE

+

+

LVD

{

{28-PIN PACKAGE ONLY

Copyright

 2000, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.