UCC5630

01/99

FEATURES

• Auto Selection Multi-Mode Single

Ended or Low Voltage Differential

Termination

• 2.7V to 5.25V Operation

• Differential Failsafe Bias

• Thermal Packaging for Low Junction

Temperature and Better MTBF

• Master/Slave Inputs

• Supports Active Negation

• Standby (Disable Mode) 5µA

• 3pF Channel Capacitance

Low Voltage Differential (LVD/SE) SCSI 9 Line Terminator

8

HS/GND

1

REG

DIFFSENS

5

L1–

4

L1+

32

L9–

31

L9+

125

+50mV TO +62.5mV

SWITCHES UP ARE SINGLE

ENDED SWITCHES DOWN ARE

LOW VOLTAGE DIFFERENTIAL

0.7 > 0.6V

2.2 > 1.9V

SE GND

SWITCH

52

110

52

125 +50mV TO +62.5mV

52

110

52

21

DIFFB

REF 2.7V

REF 1.25V

9

10

26

27

28

18

HS/GND

HS/GND

HS/GND

HS/GND

HS/GND

GND

19

MSTR/SLV

36

TRMPWR

+V

DD

REEF 1.3V

1.3V ± –0.1V

20

SOURCE 5 < 15mA

SINK 200

µAMAXIMUM(NOISELOAD)

34

LVD

33

SE

35

HIPD

0.1

µF

20k

LOW

FREQUENCY

FILTER

50Hz – 60Hz

SOURCE ONLY FROM TRMPWR AND THE ENABLED TERMINATORS

OPEN CIRCUIT ON POWER OFF

OR

OPEN CIRCUIT IN A DISABLED

TERMINATOR MODE

SOURCE/SINK

REGULATOR

HIGH IMPEDANCE

RECEIVER EVEN

WITH POWER OFF

17

DISCNCT

4.7

µF

MWP 36 PINOUT

BLOCK DIAGRAM

UDG-98049

DESCRIPTION

The UCC5630 Multi-Mode Low Voltage Differential and Single Ended Ter-

minator is both a single ended terminator and a low voltage differential ter-

minator for the transition to the next generation SCSI Parallel Interface

(SPI-2). The low voltage differential is a requirement for the higher speeds

at a reasonable cost and is the only way to have adequate skew budgets.

The transceivers can be incorporated into the controller, unlike SCSI high

power differential (EIA485) which requires external transceivers. Low Volt-

age differential is specified for Fast-40 and Fast-80, but has the potential of

speeds up to Fast-320. The UCC5630 is SPI-2, SPI and Fast-20 compliant.

Consult SSOP-36 and LQFP-48 Package Diagram for exact dimensions.

The UCC5630 can not be used with SCSI high voltage differential (HVD)

EIA485. It will shut down when it sees high power differential to protect the

bus. The pinning for high power differential is not the same as LVD or sin-

gle ended and the bias voltage, current and power are also different for

EIA485 differential.

Circuit Design Patented