DS2105
DS2105
SCSI Terminator
FEATURES
PIN ASSIGNMENT
TERMPWR1
R1
R2
R3
R4
R5
VREF1
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
PD
VREF2
R9
R8
R7
R6
NC
TERMPWR2
•
Fully
SCSI
compliant with SCSI–1, Fast SCSI and Ultra
•
Functionally compatible to the DS21S07A, targeted
for high volume applications
•
Provides active termination for nine signal lines
•
Laser–trimmed 110
5% tolerance
ohm termination resistors have
•
Low dropout voltage
•
Power–down
from the bus
mode isolates termination resistors
DS2105Z 16–PIN SOIC (150 MIL)
TERMPWR1
R1
R2
R3
R4
R5
VREF1
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
PD
VREF2
NC
R9
R8
R7
R6
TERMPWR2
•
Fully supports actively negated SCSI signals
•
Onboard thermal shutdown circuitry
•
16–pin plastic SOIC (DS2105)
DS2105S 16–PIN SOIC (300 MIL)
DESCRIPTION
Fast SCSI and Ultra SCSI require the use of active ter-
minations at both ends of every cable segment in a
SCSI system with single–ended drivers and receivers.
The DS2105 SCSI Terminator, which is fully compliant
with these standards, enables the designer to gain the
benefits of active termination: greater immunity to volt-
age drops on the TERMPWR (TERMination PoWeR)
line, enhanced high–level noise immunity, intrinsic
TERMPWR decoupling, and very low quiescent current
consumption. The DS2105, which integrates a regula-
tor and nine precise switched 110 ohm termination re-
sistors into a monolithic IC, is a functionally compatible
version of the DS21S07A. With relaxed output current
and termination tolerances, the DS2105 is intended for
high volume applications which require active termina-
tion but not the high performance of the DS21S07A.
The DS2105 is offered in both 300 mil and 150 mil SOIC
packages.
022698 1/7
DALLAS [ DALLAS SEMICONDUCTOR ]
