UCC5672 Datasheet, PDF (1/6 Pages) Texas Instruments – Multimode LVD/SE SCSI 9 Line Terminator

UCC5672
Multimode (LVD/SE) SCSI 9 Line Terminator
FEATURES
• Auto Selection Multi-Mode Single
Ended or Low Voltage Differential
Termination
• 2.7V to 5.25V Operation
• Differential Failsafe Bias
• Built-in SPI-3 Mode Change Filter/
Delay
• Meets SCSI-1, SCSI-2, Ultra2 (SPI-2
LVD) and Ultra3/Ultra160 Standards
• Supports Active Negation
• 3pF Channel Capacitance
DESCRIPTION
The UCC5672 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-3). 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 automatic mode select/change feature switches the terminator be-
tween Single Ended or LVD SCSI Termination, depending on the bus
mode. If the bus is in High Voltage Differential Mode, the terminator lines
transition into a High Impedance state.
The UCC5672 is SPI-3, SPI-2, and SCSI-2 compliant. This device is of-
fered in a 28 pin TSSOP package to minimize the footprint. The UCC5672
is also available in a 36 pin MWP package.
BLOCK DIAGRAM
2.1V
DIFFB ₁₇
0.6V
FILTER/
DELAY
HPD
LVD
SE
TRMPWR 28
TRMPWR 27
DIFSENS
REF 1.3V
DISCNCT 13
10µA
ENABLE
SOURCE/SINK
REGULATORS
SE REF
2.7V
LVD REF
1.25V
ENABLE
SW1
HS/GND 6
HS/GND 22
GND 14
MODE
SE
LVD
HPD
DISCNCT
SW1
OTHER
SWITCHES
UP
DOWN
DOWN
OPEN
UP
DOWN
OPEN
OPEN
1
REG
Note: Indicated pinout is for 28 pin TSSOP package.
SLUS414A - FEBRUARY 2000
110
56mV
–+
124 _56mV
+–
SE GROUND
SWITCH
110
56mV
–+
124 _56mV
+–
SE GROUND
SWITCH
16 DIFSENS
52
3 L1–
52
2 L1+
52
26 L9–
52
25 L9+
UDG-99125