TL-SCSI285
FIXED-VOLTAGE REGULATORS
FOR SCSI ACTIVE TERMINATION
SLVS065F – NOVEMBER 1991 – REVISED JULY 1999
PW PACKAGE
(TOP VIEW)
Fully Matches Parameters for SCSI
Alternative 2 Active Termination
Fixed 2.85-V Output
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
±1% Maximum Output Tolerance at
HEAT
SINK
HEAT
SINK
T = 25°C
J
0.7-V Maximum Dropout Voltage
620-mA Output Current
GND
OUTPUT
GND
INPUT
±2% Absolute Output Variation
Internal Overcurrent-Limiting Circuitry
Internal Thermal-Overload Protection
Internal Overvoltage Protection
HEAT
SINK
HEAT
SINK
HEAT SINK – These terminals have
an internal resistive connection to
ground and should be grounded or
electrically isolated.
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.
KC PACKAGE
(TOP VIEW)
OUTPUT
GND
INPUT
The GND terminal is in electrical
contact with the mounting base.
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-Ω and
the330-Ωresistorsrequiredforeachtransmissionlinewithapassiveterminationscheme, reducingsignificantly
the continuous system power drain. When placed in series with 110-Ω resistors, the device matches the
impedance level of the transmission cable and eliminates reflections.
The TL-SCSI285 is characterized for operation over the virtual junction temperature range of 0°C to 125°C.
AVAILABLE OPTIONS
PACKAGED DEVICES
CHIP
PLASTIC
POWER
(KC)
SURFACE
MOUNT
(PW)
FORM
(Y)
T
J
0°C to 125°C TL-SCSI285KC
TL-SCSI285PWR
TL-SCSI285Y
The PW package is only available taped and reeled. Chip forms are tested
at 25°C.
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 1999, 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
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265