MICROSEMI LX5122CDBT

LIN D O C #: 5122
UltraMAX
TM
ULTRA 27-L INE , P LUG
T
H E
I
N F I N I T E
P
O W E R
O F
I
P
N N O VA T I O N
AND
R O D U C T I O N
DESCRIPTION
The LX5122 Plug and Play UltraMAXTM terminator represents next-generation technology for SCSI termination applications. The
low-voltage BiCMOS architecture employed
in its design offers superior performance to
older passive and active techniques.
Linfinity's architecture employs highspeed adaptive elements for each channel,
providing the fastest response possible. The
channel bandwidth is typically 35MHz. The
LX5122 compares favorably to older linear
regulator approaches whose bandwidth's
are dominated by the output compensation
capacitor and are limited to the 500KHz
bandwidth region (see further discussion in
the Functional Description section).
Linfinity's architecture also eliminates the
output compensation capacitor typical in
earlier terminator designs. Each is approved
for use with SCSI-1, -2, -3, ULTRA and
beyond — providing the highest performance alternative available today.
Another key improvement of LX5122
products lies in their ability to insure reliable, error free communications even in
systems which do not necessarily adhere to
recommended SCSI hardware design guidelines, such as the use of improper cable
LX5122
P LAY SCSI T ERMINATOR
D
A T A
S
H E E T
K E Y F E AT U R E S
lengths and impedances. Frequently, this
situation is not controlled by the peripheral
or host designer and, when problems occur,
they are the first to be made aware of these
problems. The LX5122 architecture is much
more tolerant of marginal system integrations.
Recognizing the needs of portable and
configurable peripherals, the LX5122 has a
TTL compatible sleep/disable mode. Quiescent current is less than 150µA in this
mode.
Reduced component count is also inherent in the LX5122 architecture. Traditional
termination techniques require large stabilization and transient protection capacitors
of up to 20µF in value and size. The LX5122
architecture does not require these components, allowing all the cost savings associated with inventory, board space, assembly, reliability, and component costs.
The LX5122 has multiple disables for full
Plug and Play SCSI capability for Host Bus
Adapters with 3 SCSI connectors. It also
splits the upper 9 termination lines for
mixing 16-bit (wide) and 8-bit (narrow)
buses with minimal board trace
capacitance.
■ Ultra-Fast Response For Fast-20 SCSI
Applications
■ Plug and Play SCSI For Host Bus
Adapters With 3 SCSI Connectors
■ Split Disconnect For Mixing 16-Bit
(Wide) Or 8-Bit (Narrow) Buses
■ 35MHz Channel Bandwidth
■ Sleep-Mode Current Less Than 150µA
■ Hot-Swap Compatible
■ NO External Compensation Capacitors
■ Compatible With Active Negation
Drivers
■ Superior Pin-for-Pin Replacement For
The UCC5622
NOTE: For current data & package dimensions, visit our web site: http://www.linfinity.com.
PRODUCT HIGHLIGHT
R E C E I V I N G W AV E F O R M - 2 0 M H Z
D R I V I N G W AV E F O R M - 2 0 M H Z
Receiver
Driver
1 Meter, AWG 28
LX5122
LX5122
LX5268
LX5268
PA C K A G E O R D E R I N F O
TJ (°C)
0 to 125
SSOP
DB Plastic
44-pin
NOTE:
For An In-Depth
Discussion On Applying
SCSI, Request Linfinity
Application Note:
"Understanding The
Single-Ended SCSI Bus"
LX5122CDB
Note: Available in Tape & Reel.
Append the letter "T" to part number. (i.e. LX5122CDBT)
Copyright © 1999
Rev. 1.0 6/99
LINFINITY MICROELECTRONICS INC.
11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: 714-893-2570
1
PRODUCT DATABOOK 1996/1997
UltraMAX
LX5122
ULTRA 27-L INE , P LUG
P
AND
R O D U C T I O N
A B S O L U T E M A X I M U M R AT I N G S
P LAY SCSI T ERMINATOR
D
A T A
S
H E E T
PA C K A G E P I N O U T S
(Note 1)
TermPwr Voltage ..................................................................................................... 7V
Continuous Output Voltage Range .............................................................. 0 to 5.5V
Continuous Disable Voltage Range .............................................................. 0 to 5.5V
Operating Junction Temperature
Plastic (PW & DB Packages) ......................................................................... 150ºC
Storage Temperature Range ............................................................. -65°C to +150°C
Solder Temperature (Soldering, 10 seconds) ................................................... 300°C
T19
T20
T1
T2
W1
W2
T3
T4
T5
GND
GND
GND
GND
DISC1
DISC2
T6
T7
T8
T9
T10
T21
T22
Note 1. Exceeding these ratings could cause damage to the device.
T H E R M A L D ATA
PW PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
50°C/W
DB PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
50°C/W
Junction Temperature Calculation: TJ = TA + (PD x θJA).
The θJA numbers are guidelines for the thermal performance of the device/pc-board
system. All of the above assume no ambient airflow.
1
44
2
43
3
42
4
41
5
40
6
39
7
38
8
37
9
36
10
35
11
34
12
33
13
32
14
31
15
30
16
29
17
28
18
27
19
26
20
25
21
24
22
23
T27
T26
T25
T18
N1
T17
T16
T15
N.C.
GND
GND
GND
GND
VT
T14
T13
T12
N.C.
N.C.
T11
T24
T23
DB PACKAGE
(Top View)
R E C O M M E N D E D O P E R AT I N G C O N D I T I O N S
Parameter
Symbol
Termination Voltage
High Level Disable Input Voltage
Low Level Disable Input Voltage
Operating Virtual Junction Temperature Range
LX5122C
VTERM
VIH
VIL
(Note 2)
Recommended Operating Conditions
Min.
Typ.
Max.
Units
4.0
2
0
5.5
VTERM
0.8
V
V
V
0
125
°C
Note 2. Range over which the device is functional.
ELECTRICAL CHARACTERISTICS
Term Power = 4.75V unless otherwise specified. Unless otherwise specified, these specifications apply at the recommended operating ambient temperature of TA = 25°C. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to the ambient temperature.
Parameter
Symbol
Output High Voltage
TermPwr Supply Current
Output Current
Disable Input Current
VOUT
ICC
DISC1
DISC2
Output Leakage Current
Channel Bandwidth
Termination Sink Current, per Channel
2
IOUT
IIN
BW
ISINK
Test Conditions
Min.
2.65
All data lines = open
All data lines = 0.5V
DISC1 and DISC2 < 0.8V
VOUT = 0.2V
DISC1 = 0V
DISC2 = 0V
DISC1 and DISC2 < 0.8V, VO = 0.2V
VOUT = 4V
-20
LX5122
Typ.
Max.
2.85
12
635
50
-23
35
7
20
670
150
-24
-10
-10
1
Units
V
mA
mA
µA
mA
µA
µA
µA
MHz
mA
Copyright © 1999
Rev. 1.0 6/99
PRODUCT DATABOOK 1996/1997
UltraMAX
LX5122
ULTRA 27-L INE , P LUG
P
AND
R O D U C T I O N
P LAY SCSI T ERMINATOR
D
A T A
S
H E E T
BLOCK DIAGRAM
TERM POWER
CURRENT
BIASING
CIRCUIT
VCC
DISC1
24mA CURRENT
LIMITING CIRCUIT
DATA OUTPUT
PIN DB(0)
VCC
2.85V
DISC2
1.4V
1 OF 27 CHANNELS
FUNCTIONAL DESCRIPTION
Cable transmission theory suggests that in order to optimize
signal speed and quality, the termination should act both as
an ideal voltage reference when the line is released (de-asserted)
and as an ideal current source when the line is active (asserted).
Common active terminators, which consist of Linear Regulators
in series with resistors (typically 110Ω), are a compromise. As
the line voltage increases, the amount of current decreases
POWER UP / POWER DOWN FUNCTION TABLE
DISC1
DISC2
W1
W2
N1
T1-T18
L
H
H
L
L
L
L
L
L
L
L
H
L
H
L
L
L
L
L
L
L
L
DC
DC
DC
H
H
H
H
L
L
L
L
DC
DC
DC
H
H
L
L
H
H
L
L
DC
DC
DC
H
L
H
L
H
L
H
L
Enabled
Disabled
Disabled
Enabled
Enabled
Enabled
Disabled
Enabled
Disabled
Disabled
Disabled
Copyright © 1999
Rev. 1.0 6/99
linearly by the equation V = I * R. The UltraMAX LX5122, with
its unique new architecture, applies the maximum amount of
current regardless of line voltage until the termination high
threshold (2.85V) is reached.
Acting as a near ideal line terminator, the LX5122 closely
reproduces the optimum case when the device is enabled. To
enable the device the DISC1 and DISC2 pins must be driven
per the above table. During this mode of operation,
quiescent current is 12mA and the device will
respond to line demands by delivering 24mA on
T19-T27
assertion and by imposing 2.85V on de-assertion.
Disable mode places the device in a sleep state,
Disabled
where a meager 150µA of quiescent current is
Enabled
consumed. Additionally, all outputs are in a HiDisabled
Z (impedance) state. Sleep mode can be used
Enabled
for power conservation or to completely eliminate
Enabled
the terminator from the SCSI chain.
An additional feature of the LX5122 is its comEnabled
patibility with active negation drivers.
Enabled
Enabled
Enabled
Disabled
Disabled
3
PRODUCT DATABOOK 1996/1997
UltraMAX
LX5122
ULTRA 27-L INE , P LUG
P
AND
R O D U C T I O N
P LAY SCSI T ERMINATOR
D
A T A
S
H E E T
P L U G A N D P L AY S C S I D I A G R A M
Internal Narrow
Internal Wide
External
Wide
LX5122
For Plug and Play SCSI auto-termination diabling, connect pin 50 of the External Wide SCSI connector to W1 of the LX5122,
connect pin 50 of the Internal Wide SCSI connector to W2 of the LX5122, and connect pin 22 of the Internal Narrow connector
to N1 of the LX5122.
UltraMAX is a trademark of Linfinity Microelectronics Inc.
PRODUCTION DATA - Information contained in this document is proprietary to LinFinity, and is current as of publication date. This document
may not be modified in any way without the express written consent of LinFinity. Product processing does not necessarily include testing of
all parameters. Linfinity reserves the right to change the configuration and performance of the product and to discontinue product at any time.
4
Copyright © 1999
Rev. 1.0 6/99