LX5241 View Datasheet(PDF) - Microsemi Corporation

Part Name

Description

Manufacturer

LX5241

MULTIMODE SCSI TERMINATOR

Microsemi Corporation 

PRODUCT DATABOOK 1996/1997

UltraMAX

LX5241/5242/5243

MULTIMODE SCSI TERMINATOR

PRODUCTION DATA SHEET

FUNCTIONAL PIN DESCRIPTION

Pin

Designator

Description

1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-6 Negative signal termination lines for LVD mode. Signal termination lines for SE mode.

1+, 2+, 3+, 4+, 5+, 6+, 7+, 8+, 9+ Positive signal termination lines for LVD mode. Pseudo-ground lines for SE mode.

VTERM

DISCONNECT6

Power supply pin for terminator. Connect to SCSI bus TERMPWR. Must be decoupled by one 4.7µF

low-ESR capacitor for every three terminator devices. It is absolutely necessary to connect this pin to

the decoupling capacitor through a very low impedance (big traces on PCB). Keeping distances very

short from the decoupling capacitors to the VTERM pin is also critical. The value of the decoupling

capacitor is somewhat layout dependant and some applications may benefit from high-frequency

decoupling with 0.1µF capacitors right at VTERM pin.

Enables / disables terminator. See Power Down Function Table for logic levels per device.

GND6

Terminator ground pin. Connect to ground.

MASTER / SLAVE6

Sometimes referred to as M/S pin in this data sheet. Used to select which terminator is the control-

ling device. MASTER/SLAVE pin High or Open enables the DIFFSENSE output drive. Please see

MASTER/SLAVE Function Table.

DIFFSENSE6

This is a dual function pin. It drives the SCSI bus DIFFSENS line. It is also the sense pin to detect the

SCSI bus mode (LVD, SE or HVD). DIFFSENSE output drive can be disabled with Low level on the

MASTER/SLAVE pin. Please see DIFFSENSE and MASTER/SLAVE Function Tables. Internally

connected to DIFFB pin through 20kOhm resistor.

DIFFB6

Internally connected to DIFFSENSE pin through 20kOhm resistor. It can be used as a mode sense

pin when the device is a non-controlling terminator (MASTER/SLAVE pin is Low). An RC filter

(20kOhm / 0.1µF) is not required on the LX5241/42/43, as it has an internal timer.

SE6

Single-ended output; when High, terminator is operating in SE mode.

LVD6

Low Voltage Differential output. When High, terminator is operating in LVD mode.

HVD6

High Voltage Differential output. When High, terminator is operating in HVD mode.

HEATSINK6

Attached to die mounting pad, but not bonded to GND pin. Pins should be considered a heat sink

only, and not a true ground connection. It is recommeneded that these pins be connected to ground,

but can be left floating.

Copyright © 2000

Rev. 1.4 11/00

5

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