MICROSEMI LX5121CDB

LIN D O C #: 5121
TM
UltraMAX
ULTRA 27-L I N E , P L U G
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 LX5121 Plug and Play UltraMAXTM terminator represents next-generation technology
for SCSI termination applications. The lowvoltage BiCMOS architecture employed in its
design offers superior performance to older
passive and active techniques.
Linfinity's architecture employs high-speed
adaptive elements for each channel, providing
the fastest response possible. The channel
bandwidth is typically 35MHz. The LX5121
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 LX5121 products lies in their ability to ensure reliable, errorfree communications even in systems which
do not necessarily adhere to recommended
SCSI hardware design guidelines, such as the
use of improper cable lengths and imped-
LX5121
P LAY SCSI T ERMINATOR
D
A T A
S
H E E T
K E Y F E AT U R E S
ances. 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
LX5121 architecture is much more tolerant of
marginal system integrations.
Recognizing the needs of portable and
configurable peripherals, the LX5121 has a
TTL compatible sleep/disable mode. Typically, quiescent current is less than 150µA in
this mode.
Reduced component count is also inherent
in the LX5121 architecture. Traditional termination techniques require large stabilization and transient protection capacitors of up
to 20µF in value and size. The LX5121
architecture does not require these components, allowing all the cost savings associated
with inventory, board space, assembly, reliability, and component costs.
The LX5121 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 16bit (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 UCC5621
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
Driver
Receiver
1 Meter, AWG 28
LX5121
LX5121
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"
LX5121CDB
Note: Available in Tape & Reel.
Append the letter "T" to part number. (i.e. LX5121CDBT)
Copyright © 1999
Rev. 1.0 5/99
LINFINITY MICROELECTRONICS INC.
11861 W ESTERN A VENUE, G ARDEN G ROVE, CA. 92841, 714-898-8121, F AX: 714-893-2570
1
P R O D U C T D ATA B O O K 1 9 9 6 / 1 9 9 7
UltraMAX
LX5121
ULTRA 27-L I N E , P L U G
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 (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
DB PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
50°C/W
Junction Temperature Calculation: TJ = T A + (PD x θJA).
The θ JA 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
LX5121C
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 = 0.2V
Disable Pins 1 & 2 < 0.8V
VOUT = 0.2V
DISC1 = 0V
DISC2 = 0V
DISC1 and DISC2= < 0.8V, VO = 0.2V
-20
LX5121
Typ.
Max.
2.85
12
635
50
-22
35
VOUT = 4V
7
20
670
150
-24
-10
-10
1
Units
V
mA
mA
µA
mA
µA
µA
µA
MHz
mA
Copyright © 1999
Rev. 1.0 5/99
P R O D U C T D ATA B O O K 1 9 9 6 / 1 9 9 7
UltraMAX
LX5121
ULTRA 27-L I N E , P L U G
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
reproduces the optiPOWER UP / POWER DOWN FUNCTION TABLE
theory suggests that in
mum case when the
DISC1
DISC2
W1
W2
N1
T1-T18
T19-T27
order to optimize sigdevice is enabled. To
nal speed and quality,
enable the device the
H
L
DC
DC
DC
Enabled
Disabled
the
termination
DISC1 and DISC2 pins
L
H
DC
DC
DC
Disabled
Enabled
should act both as an
must be driven per the
ideal voltage referabove table. During
L
L
DC
DC
DC
Disabled
Disabled
ence when the line is
this mode of operation,
H
H
H
H
H
Enabled
Enabled
released (de-asserted)
quiescent current is
H
H
H
H
L
Enabled
Enabled
and as an ideal current
12mA and the device
H
H
H
L
H
Enabled
Enabled
source when the line
will respond to line deH
H
H
L
L
Disabled
Enabled
is active (asserted).
mands by delivering
Common active termi24mA on assertion and
H
H
L
H
H
Enabled
Enabled
nators, which consist
by imposing 2.85V on
H
H
L
H
L
Disabled
Enabled
of Linear Regulators in
de-assertion. Disable
H
H
L
L
H
Disabled
Disabled
series with resistors
mode places the device
H
H
L
L
L
Disabled
Disabled
(typically 110Ω), are a
in a sleep state, where
compromise. As the
a meager 150µA of quiline voltage increases, the amount of current decreases linearly
escent current is consumed. Additionally, all outputs are in
by the equation V = I * R. The UltraMAX LX5121, with its
a Hi-Z (impedance) state. Sleep mode can be used for power
unique new architecture, applies the maximum amount of
conservation or to completely eliminate the terminator from
current regardless of line voltage until the termination high
the SCSI chain.
threshold (2.85V) is reached.
An additional feature of the LX5121 is its compatibility with
Acting as a near ideal line terminator, the LX5121 closely
active negation drivers.
Copyright © 1999
Rev. 1.0 5/99
3
P R O D U C T D ATA B O O K 1 9 9 6 / 1 9 9 7
UltraMAX
LX5121
ULTRA 27-L I N E , P L U G
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
LX5121
For Plug and Play SCSI auto-termination diabling, connect pin 50 of the External Wide SCSI connector to W1 of the LX5121,
connect pin 50 of the Internal Wide SCSI connector to W2 of the LX5121, and connect pin 22 of the Internal Narrow connector
to N1 of the LX5121.
UltraMAX is a trademark of Linfinity Microelectronics Inc.
PRODUCTION DATA - Information contained in this document is proprietary to Lin Finity, 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 5/99