
TL-SCSI285, TL-SCSI285Y
FIXED-VOLTAGE REGULATORS FOR
SCSI ACTIVE TERMINATION
SLVS065D – NOVEMBER 1991 – REVISED SEPTEMBER 1996
1
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
Fully Matches Parameters for Alternative 2
SCSI Active Termination
Fixed 2.85-V Output
±
1% Maximum Output Tolerance at
T
J
= 25
°
C
0.7-V Maximum Dropout Voltage
620-mA Output Current
±
2% Absolute Output Variation
Internal Overcurrent Limiting Circuitry
Internal Thermal Overload Protection
Internal Overvoltage Protection
description
The TL-SCSI285 is a low-dropout (0.7-V)
fixed-voltage regulator specifically designed for
small computer systems interface (SCSI)
alternative 2 active signal termination. The
TL-SCSI285 0.7-V maximum dropout ensures
compatibility with existing SCSI systems while
providing a wide TERMPWR voltage range. At the
same time the
±
1% initial tolerance on its 2.85-V
output voltage ensures a tighter line driver current
tolerance, thereby increasing the system noise
margin.
The fixed 2.85-V output voltage of the
TL-SCSI285 supports the SCSI alternative 2
termination standard while reducing system
power consumption. The 0.7-V maximum dropout
voltage brings increased TERMPWR isolation,
making the device ideal for battery-powered
systems. The TL-SCSI285, with internal current
limiting, overvoltage protection, ESD protection,
and thermal protection offers designers enhanced
system protection and reliability.
When configured as a SCSI active terminator, the
TL-SCSI285 low-dropout regulator eliminates the
220-
and the 330-
resistors
required for each
transmission line with a passive termination
scheme, reducing significantly the continuous
system power drain. When placed in series with
110-
resistors, the device matches the imped-
ance level of the transmission cable and
eliminates reflections.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright
1996, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
1
2
3
4
5
6
7
14
13
12
11
10
9
8
NC
NC
GND
GND
GND
NC
NC
NC
OUTPUT
GND
GND
GND
INPUT
NC
N PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
GND
INPUT
GND
OUTPUT
PW PACKAGE
(TOP VIEW)
HEAT
SINK
HEAT
SINK
HEAT
SINK
HEAT
SINK
KC PACKAGE
(TOP VIEW)
OUTPUT
GND
INPUT
HEAT SINK – These terminals have
an internal resistive connection to
ground and should be grounded or
electrically isolated.
NC – No internal connection
NC
NC
GND
NC
OUTPUT
3
2
1 20 19
9 10 11 12 13
4
5
6
7
8
18
17
16
15
14
NC
NC
GND
NC
INPUT
(TOP VIEW)
N
N
N
N
N
N
N
N
N
FK PACKAGE
N
1
2
3
4
5
6
7
14
13
12
11
10
9
8
NC
NC
NC
GND
INPUT
NC
NC
NC
NC
NC
GND
OUTPUT
NC
NC
J PACKAGE
(TOP VIEW)