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12/10/2005 Rev.3.01

SS8219G

PIN DESCRIPTION (for 28pin TSSOP)

PIN

SYMBOL

DESCRIPTION

1

VREF

Reference Voltage. 2.85-volt reference in SE mode and 1.25V in LVD mode; must be connected to

a 4.7µF capacitor.

2-5,7-12,

18-21, 23-26

Rx+, Rx-

Signal Termination. (X=1,2,3,…..9)

Rx+: Ground line for single-ended or positive line for differential applications for the SCSI bus.

Rx-: Signal line/active line for single-ended or negative line in differential applications for the

SCSI bus.

6,22

NC/ HS GND No Connect/Heat Sink Ground. Should be grounded for heat sinking purpose

13

DISCNCT

Disconnect. When pulled high, the SS8219G isolates its bus pins (Rx+, Rx-) from the SCSI bus.

14

GND

Ground. Terminator ground pin. Connected to ground.

15

M/S

Master/slave. Used to select which terminator is the controlling device. M/S pin high enables

the DIFFSENSE driver.

16

DIFFSENSE Output to drive the SCSI bus DIFFSENS line.

17

DIFFB

An input pin to detect the type of device (differential or single-ended) on the SCSI bus. The

DIFFB pin should be connected by a 0.1µF capacitor to GND and by a 20k

Ω resistor to the SCSI

bus DIFFSENS line.

27,28

TPWR

Terminator Power. Connect to the SCSI TERMPWR line and de-couple with a 2.2µF capacitor.

*The VREF keeps the level at 2.85 volts, whether the DISCNCT pin is asserted or not; even if the termination mode is changed.

PIN DESCRIPTION (for 36pin SSOP)

PIN

SYMBOL

DESCRIPTION

1

VREF*

Reference Voltage. 2.85-volt reference; must be connected to a 4.7µF capacitor.

2,3

NC

No Connect. Do not connect these pins.

4-7,11-16,

22-25,

29-32

Rx+

Rx-

Signal Termination. (X=1,2,3,…..9)

Rx+: Ground line for single-ended or positive line for differential applications for the SCSI bus.

Rx-: Signal line/active line for single-ended or negative line in differential applications for the SCSI bus.

8, 9,10,26,

27,28

HS/GND

Heat Sink Ground. Connect to large area PC board traces to increase power dissipation

capability.

17

DISCNCT

Disconnect. When pulled high, the SS8219G isolates its bus pins (Rx+, Rx-) from the SCSI bus.

18

GND

Ground. Terminator ground pin. Connected to ground.

19

M/S

Master/slave. Used to select which terminator is the controlling device. M/S pin high enables

the DIFFSENSE driver.

20

DIFFSENSE Output to drive the SCSI bus DIFFSENS line.

21

DIFFB

An input pin to detect the type of device (differential or single-ended) on the SCSI bus. The

DIFFB pin should be connected by a 0.1µF capacitor to GND and 20k

Ω resistor to the SCSI bus

DIFFSENS line.

33

SE

Single ended mode indicator. It is HIGH when terminator is operating in SE mode.

34

LVD

Low Voltage Differential mode indicator. It is HIGH when terminator is operating in LVD mode.

35

HVD

High Voltage Differential mode indicator. It is HIGH when terminator is operating in HVD mode

36

TPWR

Terminator Power. Connect to SCSI bus TERMPWR line and decouple with 2.2µF capacitor.

*The VREF keeps the level at 2.85 volts, whether the DISCNCT pin is asserted or not; even if the termination mode is changed.