Microsemi

Integrated Products Division

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

Page 5

Copyright

Rev. 1.2b, 2005-08-29

LX5250/5252

9-Line Multimode SCSI Terminator

TM

®

FUNCTIONAL PIN DESCRIPTION

1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-

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. Psuedo-ground lines for SE mode.

Power supply pin for terminator. Connect to SCSI bus VTERM. Must be

absolutely necessary to connect this pin to the decoupling capacitor through a very low

impedance (big traces to PCB). Keeping distances very short from the decoupling

capacitors is somewhat layout dependent and some applications may benefit from high

DISCONNECT

Enables/Disables terminator. See Power Down Function Table for logic levels

GND

Terminator ground pin. Connect to ground.

MASTER/SLAVE

Sometimes referred to as M/S pin in this datasheet. Used to select which terminator is the

controlling device. M/S pin High or Open enables the DIFFSENSE output drive. Please

see MASTER/SLAVE Function Table.

DIFFSENSE

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 M/S pin. Please see DIFFSENSE and MASTER/SLAVE

DIFFB

mode sense pin when the device is non-controlling terminator (M/S is low). An RC filter

SE

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

LVD

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

HVD

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

HEATSINK

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 recommended that these pins be

connected to ground, but can be left floating.