DS2118M

7 of 10

PIN DESCRIPTION

PIN

NAME

FUNCTION

1

VREF

Reference Voltage. 2.85V reference in SE mode and 1.25V reference in

LVD mode; must be decoupled with a 4.7µF cap.

2, 3

NC

No Connection. Do not connect these pins.

4–7, 11–16,

22–25, 29–32

RxP,

RxN

Signal Termination. Connect to SCSI bus signal lines.

8, 10, 26, 9,

28, 27

HS GND

Heat Sink Ground. Internally connected to the mounting pad. Should

be grounded.

17

ISO

Isolation. When pulled high, the DS2118M isolates its bus pins (RxP,

FxP) from the SCSI bus.

18

GND

Ground. Signal ground; 0V.

19

MSTR/SLV

Master/Slave. Mode-select for the noncontrolling terminator. When

pulled high (MSTR), the DIFFSENSE driver is enabled.

20

DIFFSENSE DIFFSENSE. Output to drive the SCSI bus DIFFSENS line.

21

DIFF_CAP

DIFFSENSE Capacitor. Connect 0.1µF capacitor for DIFFSENSE

filter. Input to detect the type of device (differential or single-ended) on

the SCSI bus.

33

SE

Single-Ended. SE output of DIFFSENSE receiver; indicates SE bus

operation.

34

LVD

Low-Voltage Differential. LVD output of DIFFSENSE receiver;

indicates LVD bus operation.

35

HVD

High-Voltage Differential. HVD output of DIFFSENSE receiver;

indicates HVD bus operation or thermal shutdown.

36

TPWR

Termination Power. Connect to the SCSI TERMPWR line and

decouple with 2.2µF capacitor.

RECOMMENDED OPERATING CONDITIONS

PARAMETER

SYMBOL

MIN

TYP

MAX

UNITS

NOTES

SE Mode

4.0

5.5

V

Termpower

Voltage

LVD Mode

2.7

5.5

V

Logic 0

-0.3

+0.8

V

Logic 1

2.0

0.3

V

Operating Temperature

0

70

°C