Datasheet LX5122CDB Datasheet (Microsemi Corporation)

LIN DOC #:

5122

UltraMAX

ULTRA 27-LINE, PLUG AND PLAY SCSI TERMINATOR

T HE I NFINITE P OWER OF I NNOVATION

DESCRIPTION KEY FEATURES

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

NOTE: For current data & package dimensions, visit our web site: http://www.linfinity.com.

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.

P RODUCTION DATA SHEET

TM

LX5122

■ 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

PRODUCT HIGHLIGHT

DRIVING WAVEFORM - 20MHZRECEIVING WAVEFORM - 20MHZ

Receiver

1 Meter, AWG 28

LX5122 LX5122

LX5268 LX5268

PACKAGE ORDER INFO

T

(°C)

J

0 to 125 LX5122CDB

Append the letter "T" to part number. (i.e. LX5122CDBT)

Note: Available in Tape & Reel.

Plastic SSOP

DB

44-pin

Driver

NOTE:

For An In-Depth

Discussion On Applying

SCSI, Request Linfinity

Application Note:

"Understanding The

Single-Ended SCSI Bus"

Copyright © 1999
Rev. 1.0 6/99

L INF INITY MICROELECTRONICS INC.

11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: [phone]

1

PRODUCT DATABOOK 1996/1997

LX5122

ULTRA 27-LINE, PLUG AND PLAY SCSI TERMINATOR

P RODUCTION DATA SHEET

ABSOLUTE MAXIMUM RATINGS (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

Note 1. Exceeding these ratings could cause damage to the device.

THERMAL DATA

PW PACKAGE:

THERMAL RESISTANCE-JUNCTION TO AMBIENT,

DB PACKAGE:

THERMAL RESISTANCE-JUNCTION TO AMBIENT,

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.

θθ

θ

θθ

JA

θθ

θ

θθ

JA

50°C/W

50°C/W

UltraMAX

PACKAGE PIN OUTS

T19
T20

W1
W2

GND
GND
GND

GND
DISC1
DISC2

T10
T21
T22

144
243
342

T1

441

T2

540
639
738

T3

837

T4

936

T5

10 35
11 34
12 33
13 32
14 31
15 30
16 29

T6

17 28

T7

18 27

T8

19 26

T9

20 25
21 24
22 23

DB PACKAGE

(Top View)

T27
T26
T25
T18
N1
T17
T16
T15
N.C.
GND
GND
GND
GND
V

T

T14
T13
T12
N.C.
N.C.
T11
T24
T23

RECOMMENDED OPERATING CONDITIONS (Note 2)

Parameter

Termination Voltage V
High Level Disable Input Voltage V
Low Level Disable Input Voltage V
Operating Virtual Junction Temperature Range

LX5122C

Note 2. Range over which the device is functional.

Symbol

TERM

IH
IL

Recommended Operating Conditions

Min. Typ. Max.

Units

4.0 5.5 V
2V

TERM

V

0 0.8 V

0 125 °C

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

Output High Voltage V
TermPwr Supply Current I

Symbol

OUT

CC

Test Conditions Units

All data lines = open
All data lines = 0.5V

DISC1 and DISC2 < 0.8V
Output Current I
Disable Input Current DISC1 I

OUTVOUT

IN

= 0.2V

DISC1 = 0V

DISC2 DISC2 = 0V
Output Leakage Current DISC1 and DISC2 < 0.8V, VO = 0.2V
Channel Bandwidth BW
Termination Sink Current, per Channel I

SINKVOUT

= 4V

LX5122

Min. Typ. Max.

2.65 2.85 V
12 20 mA

635 670 mA

50 150 µA

-20 -23 -24 mA

-10 µA

-10 µA
1µA

35 MHz

7mA

2

Copyright © 1999

Rev. 1.0 6/99

PRODUCT DATABOOK 1996/1997

UltraMAX

V

V

CC

DISC1

CC

DISC2

1.4V

ULTRA 27-LINE, PLUG AND PLAY SCSI TERMINATOR

P RODUCTION DATA SHEET

BLOCK DIAGRAM

TERM POWER

CURRENT

BIASING

CIRCUIT

24mA CURRENT

LIMITING CIRCUIT

2.85V

LX5122

DATA OUTPUT
PIN DB(0)

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

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

POWER UP / POWER DOWN FUNCTION TABLE

DISC1 DISC2 W1 W2 N1 T1-T18 T19-T27

L H DC DC DC Enabled
H L DC DC DC
H H DC DC DC

Disabled
Disabled Disabled

L L H H H Enabled Enabled

L L H H L Enabled Enabled

L L H L H Enabled Enabled

LLHLL

Disabled

L L L H H Enabled Enabled

LLLHL

LLLLH

L L LLL

Disabled
Disabled Disabled
Disabled Disabled

Disabled

Enabled

Enabled

Enabled

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
assertion and by imposing 2.85V on de-assertion.
Disable mode places the device in a sleep state,
where a meager 150µA of quiescent current is
consumed. Additionally, all outputs are in a Hi­Z (impedance) state. Sleep mode can be used
for power conservation or to completely eliminate
the terminator from the SCSI chain.
An additional feature of the LX5122 is its com­patibility with active negation drivers.

Copyright © 1999
Rev. 1.0 6/99

3

PRODUCT DATABOOK 1996/1997

LX5122

ULTRA 27-LINE, PLUG AND PLAY SCSI TERMINATOR

P RODUCTION DATA SHEET

PLUG AND PLAY SCSI DIAGRAM

Internal Narrow

Internal Wide

LX5122

UltraMAX

External

Wide

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.

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.

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UltraMAX is a trademark of Linfinity Microelectronics Inc.

Copyright © 1999

Rev. 1.0 6/99