View LX5251_650834.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

LX5251
TM (R)
9-Line Multimode SCSI Terminator
PRODUCTION
DATA SHEET
DESCRIPTION The LX5251 is a multimode SCSI terminator that is compatible with the SCSI SPI-2 (Ultra2), SCSI SPI-3 (Ultra3 or Ultra160), and SCSI SPI-4 (Ultra320) specifications developed by the T10 standards committee for low voltage differential (LVD) termination, while providing backwards compatibility to the SCSI, SCSI-2, and SPI single-ended specifications. Multimode compatibility permits the use of legacy devices on the bus without hardware alterations. Automatic mode selection is achieved through voltage detection on the Diffsense line. The LX5251 utilizes an industry standard LVD architecture. The individual high bandwidth drivers maximize channel separation, reduce channel-to-channel noise and cross talk to insure Ultra320 performance. When the LX5251 is enabled, the differential sense (DIFFSENSE) pin supplies a voltage between 1.2V and 1.4V. In application, this pin is tied to the DIFFSENSE input of the corresponding LVD transceivers. This action enables the LVD transceiver function. DIFFSENSE is capable of supplying a maximum of 15mA. Tying the DIFFSENSE pin high places the LX5251 in a HI-Z state indicating the presence of an HVD device. Tying the pin low places the part in a single-ended mode while also signaling the multimode transceiver to operate in a single-ended mode. Recognizing the needs of portable and configurable peripherals, the LX5251 has a TTL compatible sleep/disable mode. During this sleep/disable mode, power dissipation is reduced to a meager 15uA while also placing all outputs in a HI-Z state. Also during sleep/disable mode, the DIFFSENSE function is disabled and is placed in a HI-Z state. The LX5251 also provides a master / slave function. Driving this pin high or floating the pin enables the 1.3V DIFFSENSE reference. Driving the pin low disables the on board DIFFSENSE reference and enables use of an external master reference device.
KEY FEATURES
WWW .Microsemi .C OM
Compliant with SCSI SPI-2 (Ultra2), SPI-3 (Ultra160), and SPI-4 (Ultra320) Auto-Selectable LVD or SingleEnded Termination Fast Response, No Output Capacitors Required Compatible with Active Negation Drivers 15A Supply Current in Disconnect Mode Logic Command Disconnects All Termination Lines Diffsense Line Driver Ground Driver Integrated for Single-Ended Operation Current Limit and Thermal Protection Hot-Swap Compatible (SingleEnded) Available in 24-pin TSSOP Package
IMPORTANT: For the most current data, consult MICROSEMI's website: http://www.microsemi.com
PRODUCT HIGHLIGHT
+
L X 5251
+
L X 5251
LX5251 LX5251
PACKAGE ORDER INFO Plastic TSSOP PW 24-Pin TA (C) 0 to 70 LX5251CPW
RoHS Compliant / Pb-free Transition DC: 0442
Note: Available in Tape & Reel.Append the letters "TR" to the part number. (i.e. LX5251CPW-TR)
Copyright (c) 2002 Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
LX5251
TM (R)
9-Line Multimode SCSI Terminator
PRODUCTION
DATA SHEET
ABSOLUTE MAXIMUM RATINGS Term Power (VTERM) ................................................................................................-0.3V to 7V Operating Junction Temperature .......................................................................................150C Storage Temperature Range ............................................................................... -65C to 150C Peak Package Solder Reflow Temperature (40 second maximum exposure)...... 260C (+0, -5)
Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of specified terminal.
PACKAGE PIN OUT
WWW .Microsemi .C OM
1+ 12+ 23+ 34+ 45+ 5DISC GND
1 2 3 4 5 6 7 8 9 10 11 12
24 23 22 21 20 19 18 17 16 15 14 13
VTERM NC 99+ 88+ 77+ 66+ DIFFSENSE M/Sb
THERMAL DATA
PW PACKAGE
(Top View)
PW
24 Pin Plastic TSSOP 100C/W
N/C = Not internally connected RoHS / Pb-free 100% Matte Tin Lead Finish
THERMAL RESISTANCE-JUNCTION TO AMBIENT, JA
Junction Temperature Calculation: TJ = TA + (PD x JA). The JA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow. JA can vary significantly depending on mounting technique.
MASTER/SLAVE FUNCTION TABLE Master/Slave
L* H Open (Pull-Up)
DIFFSENSE Status
HI Z 1.3V 1.3V 0mA 10mA Source 10mA Source
* When in Low state, terminator will sense state of DIFFSENS line.
DIFFSENSE/POWER UP/POWER DOWN FUNCTION TABLE
PACKAGE DATA PACKAGE DATA
DISCONNECT DIFFSENSE
L L L H or Open < 0.5V 0.7V - 1.9V > 2.4V X
Outputs Status
Enable Enable Disable Disable
Type
SE LVD HI-Z HI-Z
Quiescent Current
55mA 35mA 8mA 10A
Copyright (c) 2002 Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2
LX5251
TM (R)
9-Line Multimode SCSI Terminator
PRODUCTION
DATA SHEET
RECOMMENDED MAX OPERATING CONDITIONS
WWW .Microsemi .C OM
Parameter
LVD SE Signal Line Voltage VTerm Disconnect Input Voltage Operating Junction Temperature
Symbol
VTERM
Min
2.9 3.5 0 0 0
LX5251 Typ
Max
5.25 5.25 5.0 VTERM 125
Units
V V V C
TJ
Unless otherwise specified, the following specifications apply over the operating ambient temperature 0C TA 70C, VTerm = 4.75V, and DISC = L. LX5251 Parameter Symbol Test Conditions Units Min Typ Max
LVD Terminator Section VTerm Supply Current Common Mode Voltage Offset Voltage Differential Terminator Impedance Common Mode Impedance Output Capacitance (Note 1) Mode Change Delay Diffsense Section Diffsense Output Voltage Diffsense Output Source Current Diffsense Sink Current Single Ended Section VTerm Supply Current Termination Output High Voltage Output Current Sink Current Output Capacitance (Note 1) Output Leakage Ground Driver Impedance SEICC VO IO ISINK CO IDDQ IHP ZG VOUT = 0.2V VOUT = 4V, All lines DISC > 2.0V DISC > 2.0V ; VLINE = 0 to 4V, TA = 25 DISC > 2.0V ;VTERM = Open, VLINE = 2.7V, TA = 25 I = 1mA All tem lines = Open, Master/Slave = 0V All tem lines = 0.2V, Master/Slave = 0V DISC > 2.0V; TA = 25 2.5 18.5 40 55 250 15 2.7 22.5 65 3 2 1 100 75 290 35 3.1 24 mA mA A V mA mA pF A A VDIFF IDIFF ISINK(DIFF) VDIFF = 0V VDIFF = 2.75V 1.2 5 20 1.3 1.4 15 200 V mA A LVDICC VCM VOS ZO ZCM CO tDF Open circuit between (-) and (+) terminals VOUT Differential = -1V to +1V 0.5V to 2V DISC > 2.0V Diffsense = 1.4V to 0V 100 115 All term lines open DISC > 2.0V 1.125 100 100 110 35 15 1.25 112 105 150 45 35 1.375 125 110 195 3 300 mA A V mV pF ms
ELECTRICAL CHARACTERISTICS
ELECTRICALS
Copyright (c) 2002 Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 3
LX5251
TM (R)
9-Line Multimode SCSI Terminator
PRODUCTION
DATA SHEET
Unless otherwise specified, the following specifications apply over the operating ambient temperature 0C TA 125C, VTerm = 4.75V, and DISCONNECT = L. LX5251 Parameter Symbol Test Conditions Units Min Typ Max
DISCONNECT Section Disconnect Thresholds Input Current MASTER/SLAVE Section Master/Slave Thresholds Input Current Note 1: Guaranteed by design. VTH(MS) IIL(MS) IIH(MS) Master/Slave = 0V Master/Slave = 2.4V 0.8 100 2.0 10 V A nA VTH IIL IIH DISC = 0V DISC = 2.4V 0.8 100 10 2.0 V nA A
ELECTRICAL CHARACTERISTICS (CONTINUED)
WWW .Microsemi .C OM
BLOCK DIAGRAM
VTERM
24
1.07 mA
1 of 9 Terminator Pairs
SE LVD HVD 52.5 SE LVD 150 HVD 52.5
22.4mA I-Limited 2.7V Source LVD(-) /SE
2
DISC
11
DISC
1
LVD(+) /SE (Pseudo-GND)
1.25V 10mA I-Limited 1.3V Source
20
M/S
13
1.07 mA
12
GND
SE DIFSENSE
14
20K DIFFB
Window Comp.
HVD
LVD
POWER ON & MODE DELAY
ELECTRICALS ELECTRICALS
DISC SE
LATCH
HVD LVD
Figure 1 - LX5251 Block Diagram
Copyright (c) 2002 Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 4
LX5251
TM (R)
9-Line Multimode SCSI Terminator
PRODUCTION
DATA SHEET
FUNCTIONAL PIN DESCRIPTION
WWW .Microsemi .C OM
PIN NAME 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 91+, 2+, 3+, 4+, 5+, 6+, 7+, 8+, 9+
DESCRIPTION Negative signal termination lines for LVD mode. Signal termination lines for SE mode. Positive signal termination lines for LVD mode. Psuedo-ground lines for SE mode.
Power supply pin for terminator. Connect to SCSI bus VTERM. Musts be decoupled by one 4.7F low-ESR capacitor for every three terminator devices. It is
VTERM absolutely necessary to connect this pin to the decoupling capacitor through a very low impedance (big traces to PCB). Keeping distances very short from the decoupling capacitors is somewhat layout dependent and some applications may benefit from high frequency decoupling with 0.1F capacitors at VTERM pin.
DISCONNECT GND
Enables/Disables terminator. See Power Down Function Table for logic levels.
Terminator ground pin. Connect to ground. Sometimes referred to as M/S pin in this datasheet. Used to select which terminator is the controlling device. M/S pin High or Open enables the DIFFSENSE output drive. Please see MASTER/SLAVE Function Table. This is a dual function pin. It drives the SCSI bus DIFFSENS line. It is also the sense pin to detect the SCSI bus mode (LVD, SE, or HVD). DIFFSENSE output drive can be disabled with low level on the M/S pin. Please see DIFFSENSE and MASTER/SLAVE Function Tables. Note: Must connect Diffsense signal to Diffsense pin of LX5251.
MASTER/SLAVE
DIFFSENSE
PACKAGE DATA PACKAGE DATA
Copyright (c) 2002 Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 5
LX5251
TM (R)
9-Line Multimode SCSI Terminator
PRODUCTION
DATA SHEET
APPLICATION SCHEMATIC
WWW .Microsemi .C OM
HOST
TERMPOWER VTERM 11+ Data Lines (9) 99+
PERIPHERAL
11+ 99+ VTERM
TERMPOWER
DISCONNECT DISC GND
LX5251
LX5251
DISC GND
DISCONNECT
DIFFSENS
DIFFSENS
4.7uF
VTERM
11+ Data Lines (9) 99+
11+ 99+
VTERM
4.7uF
LX5251
DISC GND
LX5251
DISC GND
DIFFSENS
DIFFSENS
VTERM
11+ Control Lines (9) 99+
11+ 99+
VTERM
LX5251
DISC GND
LX5251
DISC
APPLICATIONS APPLICATIONS
GND DIFFSENS DIFFSENS
* DIFFB pin not present on the LX5251CPW. Must connect Diffsense signal to Diffsens pin of each terminator.
Figure 2 - Microsemi Application Schematic
Copyright (c) 2002 Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 6
LX5251
TM (R)
9-Line Multimode SCSI Terminator
PRODUCTION
DATA SHEET
MECHANICAL DRAWINGS
WWW .Microsemi .C OM
PW
24-Pin Thin Small Shrink Outline (TSSOP)
321 E P
F D AH
SEATING PLANE
B
G
L
INCHES MIN MAX 0.033 0.037 0.007 0.012 0.0035 0.008 0.303 0.311 0.169 0.177 0.025 BSC 0.002 0.005 - .0433 0.020 0.030 0 8 0.246 0.256 - 0.004
C
M
Dim A B C D E F G H L M P *LC
* Lead Coplanarity
MILLIMETERS MIN MAX 0.85 0.95 0.19 0.30 0.09 0.20 7.70 7.90 4.30 4.50 0.65 BSC 0.05 0.15 - 1.10 0.50 0.75 0 8 6.25 6.55 - 0.10
M MECHANICALS
Note:
1. Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006") on any side. Lead dimension shall not include solder coverage.
Copyright (c) 2002 Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 7
LX5251
TM (R)
9-Line Multimode SCSI Terminator
PRODUCTION
DATA SHEET
NOTES
WWW .Microsemi .C OM
N NOTES
PRODUCTION DATA - Information contained in this document is proprietary to Microsemi and is current as of publication date. This document may not be modified in any way without the express written consent of Microsemi. Product processing does not necessarily include testing of all parameters. Microsemi reserves the right to change the configuration and performance of the product and to discontinue product at any time.
Copyright (c) 2002 Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 8

▲Up To Search▲

Price & Availability of LX5251

	To Download LX5251 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .