鈥?/div>
Thermal packaging for low junction
temperature and better MTBF.
DESCRIPTION
The UCC5628 Multimode SCSI Terminator provides a smooth transition
into the next generation of the SCSI Parallel Interface (SPI-2). It automati-
cally senses the bus, via DIFFB, and switches the termination to either sin-
gle ended (SE) or low voltage differential (LVD) SCSI, dependent on which
type of devices are connected to the bus. The UCC5628 can not be used
on a HVD, EIA485, differential SCSI bus. If the UCC5628 detects a HVD
SCSI device, it switches to a high impedance state.
The Multimode terminator contains all functions required to terminate and
auto detect and switch modes for SPI-2 bus architectures. Single Ended
and Differential impedances and currents are trimmed for maximum effec-
tiveness. Fail Safe biasing is provided to insure signal integrity. Device/Bus
type detection circuitry is integrated into the terminator to provide automatic
switching of termination between single ended and LVD SCSI and a high
impedance for HVD SCSI. The multimode function provides all the per-
formance analog functions necessary to implement SPI-2 termination in a
single monolithic device.
The UCC5628 is offered in a 48 pin LQFP package for a temperature
range of 0擄C to 70擄C.
BLOCK DIAGRAM
(NOISE LOAD)
HPD
2.15V
DIFFB
34
0.6V
鈥?5mA
鈮
SOURCE
鈮も€?mA
50碌A(chǔ)
鈮
SINK
鈮?00碌A(chǔ)
REF
1.3V
1.3V
35
DIFFSEN
27
26
110
SOURCE/SINK REGULATOR
124
REF
1.25V
ALL SWITCHES
MODE
UP
SE
DOWN
LVD
OPEN
DISCNCT
56mV
鈥?+
56mV
+ 鈥?/div>
SE GND SWITCH
110
124
52.5
11
52.5
12
LVD
SE
REF
2.7V
L1鈥?/div>
L1+
10碌A(chǔ)
DISCNCT 36
56mV
鈥?+
56mV
+ 鈥?/div>
52.5
2
52.5
1
L14+
L14鈥?/div>
TRMPWR
3
SE GND SWITCH
HS/GND
25
GND
4-9
HS/GND
28-33
10
REG
4.7碌F
.
UDG-98099
SLUS302A - SEPTEMBER 1999
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