LIN D O C #: 5226 UltraMAX TM LX5226 U LT R A 1 8 - L I N E S C S I T E R M I N A T O R 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 R O D U C T I O N D DESCRIPTION The LX5226 SCSI terminator is part of Linfinity's UltraMAX family of high-performance, adaptive, non-linear mode SCSI products, which are designed to deliver true UltraSCSI performance in SCSI applications. The low-voltage BiCMOS architecture employed in its design offers superior performance to older linear passive and active techniques. Linfinity's UltraMAX architecture employs high-speed adaptive elements for each channel, thereby providing the fastest response possible — typically 35MHz, which is 100 times faster than the older linear regulator/ terminator approach used by other manufacturers. Products using this older linear regulator approach have bandwidths which are dominated by the output capacitor and which are limited to 500KHz (see further discussion in the Functional Description section). The UltraMAX architecture also eliminates the output compensation capacitor typical in earlier terminator designs. Each is approved for use with SCSI-1, -2, -3, UltraSCSI and beyond — providing the highest performance alternative available today. The LX5226 architecture is much more tolerant of marginal system integrations. A A T A S H E E T K E Y F E AT U R E S key improvement offered by the LX5226 lies in its ability to ensure reliable, error-free communications even in systems which do not adhere to recommended SCSI hardware design guidelines, such as the use of improper cable 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 the problem. To enter the disconnect mode, the disconnect pin must be driven high, thereby disconnecting the LX5226 from the SCSI bus. Quiescent current is less than 150µA in this mode. Reduced component counts is also inherent in the LX5226 architecture. Traditional termination techniques require large stabilization and transient protection capacitors of up to 20µF in value and size. The LX5226 architecture does not require these components, allowing all the cost savings associated with inventory, board space, assembly, reliability, and component costs. The LX5226 is a superior pin-for-pin replacement for the LX5207, the UC5601 / 5602 / 5610 and the UCC5610. ■ Ultra-Fast Response For Fast-20 SCSI Applications ■ 35MHz Channel Bandwidth ■ Sleep-Mode Current Less Than 150µA ■ NO External Compensation Capacitors ■ Compatible With Active Negation Drivers ■ Compatible With Passive And Active Terminations ■ Approved For Use With SCSI 1, 2, 3 And Ultra SCSI ■ Hot-Swap Compatible ■ Pin-For-Pin Compatible With LX5207, UC5601/5602 And UCC5610 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 DISC LX5226 LX5226 LX5268 LX5268 PA C K A G E O R D E R I N F O TA (°C) 0 to 70 SOWB DWP Plastic 28-pin, Power LX5226CDWP Note: All surface-mount packages are available in Tape & Reel. Append the letter "T" to part number. (i.e. LX5226CDWPT) Copyright © 1999 Rev. 1.0 5/99 DISC NOTE: For An In-Depth Discussion On Applying SCSI, Request Linfinity Application Note: "Understanding The Single-Ended SCSI Bus" LINFINITY MICROELECTRONICS INC. 11861 W ESTERN A VENUE, G ARDEN G ROVE, CA. 92841, 714-898-8121, F AX: 714-893-2570 1 PRODUCT DATABOOK 1996/1997 UltraMAX LX5226 U LT R A 1 8 - L I N E S C S I T E R M I N A T O R P 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 D A T A S H E E T PACKAGE PIN OUTS (Note 1) TermPwr Voltage ................................................................................................. +7V Signal Line Voltage ................................................................................... 0V to +7V Operating Junction Temperature Plastic (DWP Packages) ............................................................................... 150°C Storage Temperature Range .............................................................. -65°C to 150°C Lead Temperature (Soldering, 10 seconds) .................................................... 300°C DISC T1 T2 T3 T4 T5 HEAT SINK/GND GND HEAT SINK/GND T6 T7 T8 T9 VTERM Note 1. Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of the specified terminal. T H E R MAL DATA DWP PACKAGE: THERMAL RESISTANCE-JUNCTION TO LEADS, θJL 18°C/W THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA 40°C/W 1 28 2 27 3 26 4 25 5 24 6 23 7 22 8 21 9 20 10 19 11 18 12 17 13 16 14 15 GND T18 T17 T16 T15 T14 HEAT SINK/GND HEAT SINK/GND HEAT SINK/GND T13 T12 T11 T10 N.C. DWP PACKAGE (Top View) Junction Temperature Calculation: TJ = TA + (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. 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 Termpwr Voltage Signal Line Voltage Disconnect Input Voltage Operating Virtual Junction Temperature Range LX5226C VTERM (Note 2) Recommended Operating Conditions Min. Typ. Max. Units 4.0 0 0 5.5 5 VTERM 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 2 Symbol Output High Voltage TermPwr Supply Current VOUT ICC Output Current Disconnect Input Current Output Leakage Current Channel Bandwidth Termination Sink Current, per Channel IOUT IIN IOL BW ISINK Test Conditions Min. 2.65 All data lines = open All data lines = 0.2V DISC Pin > 2.0V VOUT = 0.2V DISC Pin = 0V DISC Pin = > 2.0V, VO = 0.2V -20 LX5226 Typ. Max. 2.85 10 424 50 -22 35 VOUT = 4V 7 15 450 150 -24 -10 1 Units V mA mA µA mA µA µA MHz mA Copyright © 1999 Rev. 1.0 5/99 PRODUCT DATABOOK 1996/1997 UltraMAX LX5226 U LT R A 1 8 - L I N E S C S I T E R M I N A T O R P R O D U C T I O N D A T A S H E E T BLOCK DIAGRAM FIGURE 1 — LX5226 BLOCK DIAGRAM TERM POWER CURRENT BIASING CIRCUIT 24mA CURRENT LIMITING CIRCUIT DATA OUTPUT PIN DB(0) 2.85V DISC 1.4V 1 OF 18 CHANNELS A P P L I C AT I O N S C H E M AT I C FIGURE 2 — 8-BIT SCSI SYSTEM APPLICATION PERIPHERAL TERM POWER DB (0) DB (1) DB (0) DB (1) ACK RST MSG ACK RST MSG LX5226 5V 4.7µF DISC LX5226 VTERM ~ ~ VTERM ~ ~ ~ 4.7µF DISC HOST TERM POWER 5V SCSI CABLE Copyright © 1999 Rev. 1.0 5/99 3 PRODUCT DATABOOK 1996/1997 UltraMAX LX5226 U LT R A 1 8 - L I N E S C S I T E R M I N A T O R P R O D U C T I O N D A T A S H E E T 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 (deasserted) 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 LX5226, 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 LX5226 closely reproduces the optimum case when the device is enabled. To enable the device a DISC pin must be pulled Logic Low. During this mode of operation, quiescent current is 6mA and the device will respond to line demands by delivering 24mA on assertion and by imposing 2.85V on deassertion. In order to disable the device, the DISC pin must be driven logic High. This mode of operation places the device in a sleep state where a meager 150µA of quiescent current is consumed. Additionally, all outputs are in a Hi-Z (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 LX5226 is its compatibility with active negation drivers. POWER UP / POWER DOWN FUNCTION TABLE DISC Pin Outputs Quiescent Current L H Open Enabled HI Z HI Z 15mA 150µA 150µA UltraMAX is a trademark of Linfinity Microelectronics Inc. 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. 4 Copyright © 1999 Rev. 1.0 5/99