Microsemi

Integrated Products Division

11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570

Page 1

Copyright

© 2002

Rev. 1.2b, 2005-08-29

LX5250/5252

9-Line Multimode SCSI Terminator

TM

®

DESCRIPTION

The LX5250/52 is a multimode SCSI

terminator that is compatible with the

SCSI SPI-2 (Ultra2 SCSI), SCSI SPI-3

(Ultra3 SCSI or Ultra160 SCSI), and

SCSI SPI-4 (Ultra320) specifications

developed

by

the

T10

standards

committee for low voltage differential

(LVD)

termination,

while

providing

backwards compatibility to the SCSI,

SCSI-2,

and

SPI

single-ended

specifications. Multimode compatibility

permits the use of legacy devices on the

bus

without

hardware

alterations.

Automatic mode selection is achieved

through

voltage

detection

on

the

Diffsense line.

The LX5250/52 utilizes an industry

standard

LVD

architecture.

The

individual

high

bandwidth

drivers

maximize channel separation, reduce

channel-to-channel noise and cross talk

to insure Ultra320 performance.

When the LX5250/52 is enabled, the

differential

sense

(DIFFSENSE)

pin

supplies a voltage between 1.2V and

1.4V.

In application this pin is tied to the

DIFFSENSE input of the corresponding LVD

transceivers.

This action enables the LVD

transceiver function. DIFFSENSE is capable of

supplying a maximum of 10mA.

Tying the DIFFSENSE pin high places the

LX5250/52 in a HI Z state indicating the

presence of an HVD device. Tying the pin low

places the part in a single-ended mode while

also signaling the multimode transceiver to

operate in a single-ended mode.

Recognizing the needs of portable and

configurable peripherals, the LX5250/52 has a

TTL compatible sleep/disable mode.

During

this sleep/disable mode, power dissipation is

reduced to a meager 15uA while also placing

all outputs in a HI Z state.

Also during

sleep/disable mode, the DIFFSENSE function

is disabled and is placed in a HI Z state.

The LX5250/52 also provides a master /

slave function.

Driving this pin high or

floating the pin enables the 1.3V DIFFSENSE

reference. Driving the pin low disables the on

board DIFFSENSE reference and enables use

of an external master reference device.

IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com

KEY FEATUR ES

Compliant with SCSI SPI-2

(Ultra2), SPI-3 (Ultra160), and

SPI-4 (Ultra320)

Auto-Selectable LVD or Single-

Ended Termination

Fast Response, No Output

Capacitors Required

Compatible with Active Negation

Drivers

15µA Supply Current in

Disconnect Mode

Logic Command Disconnects All

Termination Lines

Diffsense Line Driver

Ground Driver Integrated for

Single-Ended Operation

Current Limit and Thermal

Protection

Hot-Swap Compatible (Single-

Ended)

Available in 36-pin QSOP and 28-

pin TSSOP package

LX5250, 36-pin QSOP: Pin

Compatible With DS2118,

UCC5630A and UCC5672

LX5250 28-pin TSSOP: Pin

Compatible with DS2119, and

UCC5672

PRODUCT H I GHLIGHT

L X 5250/

L X 5252

L X 5250/

L X 5252

+

-

+

-

PACKAGE ORDER INFO

DB

QSOP

36-Pin

PW

TSSOP

28-Pin

RoHS Compliant / Pb-free

Transition DC: 0535

RoHS Compliant / Pb-free

Transition DC: 0518

0 to 70

LX5250CDB

LX5252CDB

LX5250CPW

-

Note: Available in Tape & Reel.

Append the letters “TR” to the part number. (i.e. LX5250CDB-TR)