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LIN DOC #:
5205
LX5205
18-LINE PLUG AND PLAY, µPOWER SCSI TERMINATOR
THE INFINITE POWER OF INNOVATION
DESCRIPTION
The LX5205 is an eighteen line active terminator for the SCSI parallel bus. This SCSI
standard recommends active termination at
both ends of the SCSI bus.
During disconnect mode, the LX5205
requires a meager 500nA of supply current
while offering only 2.5pF of output capacitance. To enter this low power mode, the
disconnect pins can be left open (floating)
or driven low thereby disconnecting the
terminating resistors and placing the internal
low dropout regulator into low power
mode. In disconnect mode each termination
line presents a high impedance to the SCSI
bus with the overall effect being to preserve
high signal integrity and subsequent reliable, error free communications. The
LX5205 has two disconnect pins for SCSI
Plug and Play (PnP) applications.
IMPORTANT: For the most current data, consult LinFinity's web site: http://www.linfinity.com.
During normal operation, the LX5205
consumes only 800µA of current which is
the lowest enabled supply current of any
terminator available on the market today.
Linfinity's proprietary BiCMOS low dropout
regulator architecture enables this unique
and very efficient operating characteristic.
The LX5205 also offers a precisely
trimmed channel output current specified
to a 5% tolerance. The maximum value of
the output current is trimmed as closely as
possible to the SCSI standard maximum
specification to give the highest possible
noise margin for fast SCSI operation. And
finally, the LX5205 sinks up to 100mA of
current making it compatible with today's
fast active negation drivers.
The LX5205 is a superior, pin-for-pin
replacement for the UC5607.
PRODUCT HIGHLIGHT
P RELIMINARY DATA SHEET
KEY FEATURES
■ SCSI PLUG AND PLAY, DUAL LOW
DISCONNECT, LOGIC LOW COMMAND
DISCONNECTS ALL TERMINATION LINES
■ 2.5pF OUTPUT CAPACITANCE DURING
DISCONNECT
■ 500nA SUPPLY CURRENT IN DISCONNECT
MODE
■ 800µA SUPPLY CURRENT DURING NORMAL
OPERATION
■ 100mA SINK CURRENT FOR ACTIVE
NEGATION
■ LOGIC COMMAND DISCONNECTS ALL
TERMINATION LINES
■ CURRENT LIMIT AND THERMAL PROTEC-
TION
■ COMPATIBLE WITH SCSI 1, 2, 3, AND
FAST-20 STANDARDS
■ HOT SWAP COMPATIBLE
RECEIVING WAVEFORM - 20MHZ DRIVING WAVEFORM - 20MHZ
Driver
LX5205
PnP
Disconnect 1
Disconnect 2
Disconnect 1
Disconnect 2
LX5205
PnP
Receiver
1 Meter, AWG 28
LX5268 LX5268
NOTE:
PACKAGE ORDER INFO
T
(°C)
A
0 to 70 LX5205CDWP
Note: All surface-mount packages are available in Tape & Reel.
Append the letter "T" to part number. (i.e. LX5205CDWPT)
Plastic SOWB
DWP
28-pin, Power
For An In-Depth
Discussion On Applying
SCSI, Request Linfinity
Application Note:
"Understanding The
Single-Ended SCSI Bus"
Copyright © 1998
Rev. 0.7 3/98
L INFINITY MICROELECTRONICS INC.
11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: 714-893-2570
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LX5205
PRODUCT DATABOOK 1996/1997
18-LINE PLUG AND PLAY, µPOWER SCSI TERMINATOR
RELIMINARY DATA SHEET
P
ABSOLUTE MAXIMUM RATINGS (Note 1)
TermPwr Voltage .................................................................................................+7V
Signal Line Voltage ................................................................................... 0V to +7V
Regulator Output Current ................................................................................... 1.2A
Operating Junction Temperature
Plastic (DWP Package)................................................................................. 150°C
Storage Temperature Range .............................................................. -65°C to 150°C
Lead Temperature (Soldering, 10 seconds) .................................................... 300°C
Note 1. Exceeding these ratings could cause damage to the device. All voltages are with
respect to Ground. Currents are positive into, negative out of the specified
terminal.
THERMAL DATA
DWP PACKAGE:
D
θθ
θ
θθ
JL
x θ
θθ
θ
θθ
JA
).
JA
THERMAL RESISTANCE-JUNCTION TO LEADS,
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
Junction Temperature Calculation: TJ = TA + (P
numbers are guidelines for the thermal performance of the device/pc-board
The θ
JA
system. All of the above assume no ambient airflow.
18°C/W
40°C/W
POWER UP / POWER DOWN FUNCTION TABLE
Disconnect 1 Disconnect 2 Outputs
H H Disabled 0.5µA
H L Enabled 800µA
L H Enabled 800µA
L L Disabled 80µA
Open Open Disabled 0.5µA
DISCONNECT 1
HEAT SINK/GND
HEAT SINK/GND
Quiescent
Current
PACKAGE PIN OUTS
T1
T2
T3
T4
T5
GND
T6
T7
T8
T9
V
TERM
DWP PACKAGE
(Top View)
128
227
326
425
524
623
722
821
920
10 19
11 18
12 17
13 16
14 15
DISCONNECT 2
T18
T17
T16
T15
T14
HEAT SINK/GND
HEAT SINK/GND
HEAT SINK/GND
T13
T12
T11
T10
REG OUT
2
Copyright © 1998
Rev. 0.7 3/98
Page 3
PRODUCT DATABOOK 1996/1997
LX5205
18-LINE PLUG AND PLAY, µPOWER SCSI TERMINATOR
P RELIMINARY DATA SHEET
RECOMMENDED OPERATING CONDITIONS (Note 2)
Parameter
Termpwr Voltage V
Symbol
TERM
Signal Line Voltage
Disconnect Input Voltage
Output Capacitance on REGOUT
Operating Virtual Junction Temperature Range
LX5205C
Note 2. Range over which the device is functional.
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply over the operating ambient temperature range of 0°C ≤ TA ≤ 70°C. Termpwr = 4.75V,
DISCONNECT 1 = DISCONNECT 2 = 2.2V. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures
equal to the ambient temperature.)
Parameter
Symbol
Test Conditions Units
Supply Current Section
Termpwr Supply Current All term lines Open
All term lines 0.5V
Power Down Mode DISCONNECT 1,2 = Open
Output Section (Terminator Lines)
Terminator Impedance I
Terminator Output High Voltage
Max. Output Current V
Output Leakage DISCONNECT 1,2 = Open, V
Output Capacitance DISCONNECT 1,2 = Open
Sink Current V
= -5mA to -15mA
TERM
= 0.5V, TA = 25°C
OUT
V
= 0.5V, 0°C ≤ TA ≤ 70°C
OUT
V
OUT
V
OUT
OUT
= 0.5V, V
= 0.5V, V
= 4V
= 4V, TA = 25°C
TERM
= 4V
TERM
= 0V to 5.25V
TERM
Regulator Section
Regulator Output Voltage
Line Regulation V
Load Regulation I
Drop Out Voltage I
Short Circuit Current V
= 4V to 6V
TERM
= 0 to -100mA
REG
= -100mA
REG
= 0V
REG
Thermal Shutdown
Disconnect Section
Disconnect Threshold
Input Current Disconnect 1 = Disconnect 2 = 0V
Disconnect 1 = Disconnect 2 = 2.2V
Recommended Operating Conditions
Min. Typ. Max.
4 5.25 V
05V
0V
TERM
4.7 µF
0 125 °C
LX5205
Min. Typ. Max.
0.8 1.5 mA
390 415 mA
0.5 1 µA
100 110 120 Ω
2.7 2.9 V
-20.3 -21.8 -23 mA
-19.0 -21.8 -23 mA
-19.5 -21.8 -23 mA
-18.0 -21.8 -23 mA
10 400 nA
2.5 pF
58 70 mA
3.6 V
10 20 mV
20 50 mV
0.45 1.0 V
-700 -1000 mA
150 °C
0.8 2.0 V
-28 µA
-25 µA
Units
V
Copyright © 1998
Rev. 0.7 3/98
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LX5205
DISCONNECT 1
DISCONNECT 2
PRODUCT DATABOOK 1996/1997
18-LINE PLUG AND PLAY, µPOWER SCSI TERMINATOR
RELIMINARY DATA SHEET
P
BLOCK DIAGRAM
FIGURE 1 — LX5205 BLOCK DIAGRAM
REG OUT
V
TERM
V
TERM
Channel
1 of 18
5V
4.7µF
TERM POWER
V
TERM
LX5205
VBG
APPLICATION SCHEMATIC
FIGURE 2 — 8-BIT SCSI SYSTEM APPLICATION
Narrow Narrow
~
DB (0)
~
DB (1)
HOST
PERIPHERAL
DB (0)
DB (1)
T0
V
TERM
T17
TERM POWER
V
TERM
5V
4.7µF
LX5205
PnP
DISCONNECT
4.7µF
REGOUT
~
ACK
~
RST
~
MSG
ACK
RST
MSG
REGOUT
4.7µF
PnP
DISCONNECT
SCSI CABLE
PRELIMINARY DATA - Information contained in this document is pre-production data, and is proprietary to LinFinity. It may
not modified in any way without the express written consent of LinFinity. Product referred to herein is offered in sample form
only, and Linfinity reserves the right to change or discontinue this proposed product at any time.
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Copyright © 1998
Rev. 0.7 3/98
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