3

UCC5622

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Regulator Section

Regulator Output Voltage

2.6

2.8

3.0

V

Drop Out Voltage

All Termination Lines = 0.2V

0.4

0.8

V

Short Circuit Current

650

900

–1300

mA

Sinking Current Capability

300

500

900

mA

Thermal Shutdown

170

°C

Thermal Shutdown Hysteresis

10

°C

Disconnect Section

Disconnect Threshold DISCNCT1

Controls Lines 10 to 27

0.8

1.5

2.0

V

Input Current DISCNCT1

DISCNCT1 = 0V

–10

–30

A

Disconnect Threshold DISCNCT2

Controls Lines 1 to 9

0.8

1.5

2

V

Input Current DISCNCT2

DISCNCT2 = 0V

–10

–30

A

Note 1: Measuring each termination line while other 26 are low (0.2V).

Note 2: Ensured by design. Not 100% tested in production.

Z

VN L

V

Iat

V

OUT

OUT

=

−

..

.

.

02

20

PIN DESCRIPTIONS

DISCNCT1: Disconnect one controls termination lines

10 – 27. Taking this pin high or leaving it open causes

termination lines 10 - 27 to become high impedance, tak-

ing this pin low allows the channels to provide normal ter-

mination.

DISCNCT2: Disconnect two controls termination lines

1 – 9. Taking this pin high or leaving it open causes

termination lines 1-9to become high impedance. Taking

this pin low allows the channels to provide normal

termination. Taking both disconnect pins high or leaving

them open will put the chip in to sleep mode where it will

be in low-power mode.

GND: Ground reference for the IC.

L1 – L27: 110

termination channels.

REG: Output of the internal 2.7V regulator.

TRMPWR: Power for the IC.

TRMPWR

REG

TO SCSI BUS

TRMPWR

DISCNCT1

DATA BYTE 1

AND CONTROL BITS

L27

L10

4.7

µF

4.7

µF

DISCNCT2

TO DRIVERS

AND RECEIVERS

UC5622

DATA BYTE 2

L9

L1

DISCNCT1 CONTROLS BITS 10 THRU 27

DISCNCT2 CONTROLS BITS 1 THRU 9

Figure 1. Typical Wide SCSI Bus Configuration Using the UCC5622

UDG-98172