LX5255 ® TM 9-Line LVD SCSI Terminator P RODUCTION DATA SHEET KEY FEATURES DESCRIPTION Compliant with SPI-2 (Ultra2), SPI-3 (Ultra160), and SPI-4 (Ultra320) 2.5pF Maximum Disabled Output Capacitance Fast Response, No External Capacitors Required 5µA Supply Current in Disconnect Mode 30mA Supply During Normal Operation Logic Command Disconnects All Termination Lines DIFSENS Line Driver Current Limit and Thermal Protection Pin Compatible With Unitrode UCC5640 supplies a voltage between 1.2V and 1.4V. In application, the terminator DIFFB input is connected to the system DIFSENS line. If there are no single ended or High Voltage Differential (HVD) devices attached to the system, the LVD output will be enabled. If the DIFSENS line is LOW, indicating a single ended device, the LX5255 output will be HiZ. If the DIFSENS line is HIGH, indicating a HVD device, the LX5255 output will be HiZ. The LX5255 has a TTL compatible sleep/disable mode. Applying a logic HIGH to the DISC pin puts the LX5255 in sleep mode. During sleep mode, power dissipation is reduced to a meager 5μA while also placing all outputs and the DIFSENS function in a HiZ state. WWW . Microsemi .C OM The LX5255 is a Low Voltage Differential (LVD) terminator designed to comply with the LVD termination specification in the SPI-4 document. The LX5255 is specifically designed for LVD only applications. Because the LX5255 supports only LVD, it has lower output capacitance than multimode terminators such as the LX5250. The LX5255 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 LX5255 is enabled, the Differential Sense (DIFSENS) pin IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com TYPICAL APPLICATION - L X 5255 - + + L X 5255 LX5255 LX5255 Typical Application PACKAGE ORDER INFO Plastic TSSOP PW 24-Pin TA (°C) RoHS Compliant / Pb-free Transition DC: 0442 0 to 70 LX5255CPW Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX5255CPW-TR) Copyright © 2000 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 LX5255 ® TM 9-Line LVD SCSI Terminator P RODUCTION ABSOLUTE MAXIMUM RATINGS PACKAGE PIN OUT NC 1+ 12+ 23+ 34+ 4DIFFB DIFSENS GND 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. THERMAL DATA PW 1 24 2 23 3 22 4 21 5 20 6 19 7 18 8 17 9 16 10 15 11 14 12 13 VTERM 99+ 88+ 77+ 66+ 55+ DISC PW PACKAGE (Top View) NC – No Internal Connection 24L TSSOP WWW . Microsemi .C OM Term Power (VTERM)............................................................................................-0.3V to 7V Signal Line Voltage .............................................................................................-0.3V to 7V Differential Voltage .............................................................................................-0.3V to 7V Operating Junction Temperature.................................................................................. 150°C Storage Temperature Range........................................................................... -65°C to 150°C Peak Package Solder Reflow Temperature (40 second maximum exposure) . 260°C (+0, -5) Note: DATA SHEET RoHS / Pb-free 100% Matte Tin Lead Finish THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 100°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. θJA can vary significantly depending on mounting technique. (See Application Notes Section: Thermal considerations) DIFFB/POWER UP/POWER DOWN FUNCTION TABLE DISC Outputs DIFFB Status Type Quiescent Current L L < 0.5V Disable HI-Z 8mA L 0.7V to 1.9V Enable LVD 30mA L H > 2.4V Disable HI-Z 8mA H or Open X Disable HI-Z 10µA RECOMMENDED MAX OPERATING CONDITIONS Parameter Symbol VTERM LX5255 Typ 2.7 Max Units 5.25 V V Signal Line Voltage 0 5.0 Disconnect Input Voltage 0 VTERM V 0 70 °C Operating Junction Temperature Copyright © 2000 Rev. 1.1, 2006-02-27 TJ Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 PACKAGE DATA VTerm Min Page 2 LX5255 ® TM 9-Line LVD SCSI Terminator P RODUCTION DATA SHEET ` ` LVD Terminator Section ICC Common Mode Voltage VCM Offset Voltage (Note 1) VOS Open circuit between (-) and (+) terminals Differential Terminator Impedance ZD VOUT Differential = -1V to +1V Common Mode Impedance ZCM 0.5V to 2V Output Capacitance (Note 2) CO DISCONNECT > 2.0V Mode Change Delay tDF DIFSENS = 1.4V to 0V 30 5 1.25 35 20 1.375 mA µA V 100 112 125 mV 100 105 110 Ω 110 150 190 Ω 3 pF 100 115 300 ms 1.2 1.3 1.4 V 1.125 DIFSENS Section DIFSENS Output Voltage DIFSENS Output Source Current DIFSENS Sink Current ` All term lines open DISCONNECT > 2.0V VTerm Supply Current WWW . Microsemi .C OM ELECTRICAL CHARACTERISTICS Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C ≤ TA ≤ 70°C, VTerm = 3.3V, and DISCONNECT = 0V. LX5255 Parameter Symbol Test Conditions Units Min Typ Max VDIFF IDIFF DIFSENS = 0V 5 15 mA ISINK(DIFF) VTERM = 2.75V 20 200 µA 0.8 2.0 V 10 µA Disconnect Section Disconnect Threshold VTH Input Current IIH DISCONNECT = 0V Note 1: Open Circuit failsafe voltage. Note 2: Guaranteed by design. ELECTRICALS Copyright © 2000 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 LX5255 ® TM 9-Line LVD SCSI Terminator P RODUCTION DATA SHEET VTERM DISC 24 13 1 of 9 Lines 1.07 mA DISC WWW . Microsemi .C OM BLOCK DIAGRAM HVD LVD 3 LVD(-) 2 LVD(+) SE 52.5 150 HVD 52.5 LVD 1.25V SE 1.07 mA 10mA I-Limited 1.3V Source DIFSENS DIFFB 11 10 12 GND DISC - SE Window Comp. + HVD LATCH LVD POWER ON & MODE DELAY Figure 1 – LX5255CPW Block Diagram FUNCTIONAL PIN DESCRIPTION PIN NAME DESCRIPTION 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9- Negative signal termination lines for LVD mode. 1+, 2+, 3+, 4+, 5+, 6+, 7+, 8+, 9+ Positive signal termination lines for LVD mode. 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 0.1µF capacitors at VTERM pin. DISC Enables/Disables terminator. See Power Down Function Table for logic levels. GND Terminator ground pin. Connect to ground. DIFSENS DIFFB Differential sense pin connected to system DIFFSENS line. Drives the SCSI bus DIFSENS line to 1.3V. Used to detect the SCSI bus mode (SE, LVD or HVD). Should be connected to a 4.7uF capacitor to GND, and a 50KΩ resistor to the DIFFSENS pin (see Figure 2 on page 5). 5 Copyright © 2000 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 PACKAGE DATA Power supply pin for terminator. Connect to SCSI bus VTERM. Must be decoupled by one 4.7µF low-ESR capacitor for every three terminator devices. It is LX5255 ® TM 9-Line LVD SCSI Terminator P RODUCTION DATA SHEET PERIPHERAL HOST TERMPOWER 11+ VTERM 11+ WWW . Microsemi .C OM APPLICATION TERMPOWER VTERM Data Lines (9) LX5255 DISCONNECT 99+ 99+ LX5255 GND GND DIFSENS DIFFB DIFSENS DIFFB NC* 50k Pin 1 4.7uF 4.7uF DISCONNECT DISC DISC VTERM 50k 4.7uF 4.7uF 11+ 11+ NC* Pin 1 4.7uF VTERM 4.7uF Data Lines (9) LX5255 99+ 99+ LX5255 DISC DISC GND GND DIFSENS DIFSENS DIFFB DIFFB NC* Pin 1 4.7uF NC* Pin 1 11+ VTERM 11+ 4.7uF VTERM Control Lines (9) LX5255 99+ 99+ LX5255 DISC DISC GND GND DIFSENS DIFSENS Pin 1 NC* Pin 1 APPLICATIONS 4.7uF DIFFB DIFFB NC* 4.7uF * The capacitor on Pin 1 can be placed on the LX5255PCW to be pin compatible with other devices. This capacitor is not required. Figure 2 – Suggested Microsemi LX5255 Universal Application Schematic Copyright © 2000 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 LX5255 ® TM 9-Line LVD SCSI Terminator P RODUCTION DATA SHEET PW WWW . Microsemi .C OM MECHANICAL DRAWINGS 24-Pin Thin Small Shrink Outline (TSSOP) 3 21 P E F D A H SEATING PLANE Dim G 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 L C M 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 * Lead Coplanarity 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 © 2000 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 MECHANICALS A B C D E F G H L M P *LC B LX5255 TM ® 9-Line LVD SCSI Terminator P RODUCTION DATA SHEET WWW . Microsemi .C OM NOTES 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 © 2000 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