OF

1

Copyright

© 2000

Rev. 1.4,2000-11-28

LX5241/5242/5243





The

LX5241/42/43

is

a

multimode

SCSI

terminator that is compatible with to the SCSI

SPI02 (Ultra2 SCSI), SCSI SPI-3 (Ultra3 SCSI or

Ultra160

SCSI),

and

pending

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

LX5241/42/43

utilizes

Linfinity’s

UltraMAX technology which delivers the ultimate

in SCSI bus performance while saving component

cost and board area. Elimination of the external

capacitors also mitigates the need for a lengthy

capacitor selection process.

The individual high

bandwidth

drivers

also

maximize

channel

separation and reduce channel to channel noise and

cross talk. The high bandwidth architecture insures

ULTRA2 performance while providing a clear

migration path to ULTRA3 and beyond.

When

the

LX5241/42/43

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 15mA. Tying the DIFFSENSE pin high places

the LX5241/42/43 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 LX5241/42/43 have

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.

Another key feature of the LX5241/42/43 is the

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

 

 

Ended Termination

Capacitance

Capacitors Required

Drivers

Disconnect Mode

Termination Lines

Single-Ended Operation

Protection

Ended)

Termination Only

and UCC5630


 


 

0V

-100mV

100mV

NEGATED

L X 52 41

L X 52 41

+

-

+

-

  

DB

Plastic TSSOP

36-Pin

PW

Plastic TSSOP

24-Pin

PW

Plastic TSSOP

28-Pin

LX5241CDBK

LX5241CPWK

LX5243CPW

0 to 70

LX5242CDBK

LX5242CPWK

-

Note: Available in Tape & Reel.

Append the letter “T” to the part number. (i.e. LX5241CDBT)