DS2117M

6 of 9

PIN DESCRIPTION Table 1

PIN

SYMBOL

DESCRIPTION

1VREF

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

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

2, 3

NC

No Connect. 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 DS2117M isolates its bus pins (RxP,

RxN) from the SCSI bus.

18

GND

Ground. Signal ground; 0.0 volts.

19

MSTR/SLV

Master/slave. Mode select for the non-controlling 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 0.1 µF 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; output high

indicates SE bus operation.

34

LVD

Low Voltage Differential. LVD output of DIFFSENSE receiver;

output high indicates LVD bus operation.

35

HVD

High Voltage Differential. HVD output of DIFFSENSE receiver;

output high indicates HVD bus operation or thermal shutdown.

36

TPWR

Termination Power. Connect to the SCSI TERMPWR line and

decouple with 2.2 µF capacitor.

RECOMMENDED OPERATING CONDITIONS

PARAMETER

SYMBOL

MIN

TYP

MAX

UNITS

NOTES

Termpower Voltage

SE mode

LVD mode

4.0

2.7

5.5

5.5

V

V

Logic 0

-0.3

+0.8

V

Logic 1

2.0

V

Operating Temperature

070

°C