3

UCC5638

PIN DESCRIPTIONS

DIFFB: Diff sense filter pin should be connected at a

0.1 F capacitor.

DIFFSENS: The SCSI bus Diff Sense line to detect what

types of devices are connected to the SCSI bus.

DISCNCT: Disconnect pin shuts down the terminator

when it is not at the end of the bus. The disconnect pin

low enables the terminator.

Note: In Disconnect Mode, the comparitor set powers down for

low idle current.

LINE

tive line in differential applications for the SCSI bus.

LINE

differential applications for the SCSI bus.

REG: Regulator bypass pin, must be connected to a

F capacitor.

terminator with a 4.7

µF capacitor to ground.

TRMPWR = 3.3V.

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Single Ended Termination Section

Impedance

Z

VL

V

IL

X

X

=

−

(.

)

02

, (Note 3)

102.3

110

117.7

Termination Current

Signal Level 0.2V, All Lines Low

–21

–24

–25.4

mA

Signal Level 0.5V

–18

–22.4

mA

Output Leakage

400

nA

Output Capacitance

Single Ended Measurement to Ground (Note 1)

3

pF

Single Ended GND SE Impedance

I= 10mA

20

60

Disconnect and Diff Buffer Input Section

DISCNCT Threshold

0.8

2.0

V

DISCNCT Input Current

10

30

A

Diff Buffer Single Ended to LVD Threshold

0.5

0.7

V

Diff Buffer LVD to HPD Threshold

1.9

2.4

V

DIFFB Input Current

–10

10

A

Note 1: Guaranteed by design. Not 100% tested in production.

12

.

–

(

max)

(

min)

V

II

VCM

VCM