Microsemi Corporation LX5121CDB Datasheet

LIN DOC #:

5121

T HE I NFINITE P OWER OF I NNOVATION

DESCRIPTION KEY FEATURES

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-

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.

TM

UltraMAX

LX5121

ULTRA 27-LINE, PLUG AND PLAY SCSI TERMINATOR

P RODUCTION DATA SHEET

■ 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

DRIVING WAVEFORM - 20MHZRECEIVING WAVEFORM - 20MHZ

Receiver

1 Meter, AWG 28

LX5121 LX5121

LX5268 LX5268

PACKAGE ORDER INFO

(°C)

T

J

0 to 125 LX5121CDB

Append the letter "T" to part number. (i.e. LX5121CDBT)

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 5/99

L INF INITY MICROELECTRONICS INC.

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

1

PRODUCT DATABOOK 1996/1997

LX5121

ULTRA 27-LINE, PLUG AND PLAY SCSI TERMINATOR

RODUCTION DATA SHEET

P

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 (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

DB PACKAGE:

D

x θ

θθ

θ

θθ

JA

).

JA

THERMAL RESISTANCE-JUNCTION TO AMBIENT,

Junction Temperature Calculation: TJ = TA + (P
The θ

numbers are guidelines for the thermal performance of the device/pc-board

JA

system. All of the above assume no ambient airflow.

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

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

DB PACKAGE

(Top View)

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

LX5121C

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 = 0.2V

Disable Pins 1 & 2 < 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

LX5121

Min. Typ. Max.

2.65 2.85 V

12 20 mA

635 670 mA

50 150 µ A

-20 -22 -24 mA

-10 µA

-10 µA
1µA

35 MHz

7mA

2

Copyright © 1999

Rev. 1.0 5/99