UC5601 SCSI Active Terminator FEATURES DESCRIPTION • Complies with SCSI, SCSI-2 Standards • 10pF Channel Capacitance During Disconnect The UC5601 provides precision resistive pull-up to a 2.9V reference for all 18 lines in a Small Computer Systems Interface (SCSI) bus cable. The SCSI-2 standard recommends active termination at both ends of every cable segment utilizing single ended drivers and receivers. • Active Termination for 18 Lines • Logic Command Disconnects all Termination Lines • Low Supply Current in Disconnect Mode • Trimmed Regulator for Accurate Termination Current • Current Limit and Thermal Shutdown Protection • 110 Ohm Termination • Meets SCSI Hot Plugging Internal circuit trimming is utilized, first to reduce resistor tolerances to ±3% and then to adjust the regulator’s output voltage to insure termination current accuracy of ±3%. The UC5601 provides a disconnect feature which, upon a logic command, disconnects all terminating resistors, and turns off the regulator; greatly reducing standby power. Other features include negative clamping on all signal lines, 20mA of active negation sink current capability, regulator current limiting, and thermal shutdown protection. This device is offered in low thermal resistance versions of the industry standard 28 pin wide body SOIC and PLCC, as well as a 24 pin DIL plastic package. BLOCK DIAGRAM UDG-94060 Circuit Design Patented 10/94 UC5601 ABSOLUTE MAXIMUM RATINGS CONNECTION DIAGRAMS Termpwr Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7V Signal Line Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to +7V Regulator Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1A Storage Temperature . . . . . . . . . . . . . . . . . . . −65°C to +150°C Operating Temperature . . . . . . . . . . . . . . . . . −55°C to +150°C Lead Temperature (Soldering, 10 Sec.) . . . . . . . . . . . . . +300°C Unless otherwise specified all voltages are with respect to Ground. Currents are positive into, negative out of the specified terminal. Consult Packaging Section of Unitrode Integrated Circuits databook for thermal limitations and considerations of packages. PLCC-28 (Top View) QP Package RECOMMENDED OPERATING CONDITIONS Termpwr Voltage . . . . . . . . . . . . . . . . . . . . . . . . . 4.0V to 5.25V Signal Line Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to +3V Disconnect Input Voltage . . . . . . . . . . . . . . . . . . 0V to Termpwr * QP package pins 12 - 18 serve as both heatsink and signal ground. SOIC-28 (Top View) DWP Package DIL-24 (Top View) N or J Package * DWP package pin 28 serves as signal ground; pins 7, 8, 9, 20, 21, 22 serve as heatsink/ground. Note: Drawings are not to scale. 2 UC5601 ELECTRICAL CHARACTERISTICS Unless otherwise stated, these specifications apply for TA = 0°C to 70°C. TRMPWR = 4.75V, DISCNCT = 0V. TA = TJ. PARAMETER Supply Current Section Termpwr Supply Current TEST CONDITIONS MIN All termination lines = Open All termination lines = 0.5V DISCNCT = Open Power Down Mode Output Section (Termination Lines) Termination Impedance ∆ILINE = -5mA to -15mA Output High Voltage VTRMPWR = 4V (Note 1) Max Output Current VLINE = 0.5V VLINE = 0.5V, TRMPWR = 4V (Note 1) Output Clamp Level ILINE = -30mA Output Leakage TRMPWR = 0V to 5.25V VLINE = 0 to 4V REG = 0V VLINE = 5.25V DISCNCT = 4V TRMPWR = 0V to 5.25V, REG = Open VLINE = 0V to 5.25V Output Capacitance DISCNCT = Open (Note 2) Regulator Section Regulator Output Voltage Line Regulation TRMPWR = 4V to 6V Load Regulation IREG = 0 to -400mA Drop Out Voltage All Termination Lines = 0.5V Short Circuit Current VREG = 0V Current Sink Capability VREG = 3.5V Thermal Shutdown Disconnect Section Disconnect Threshold Threshold Hysteresis Input Current DISCNCT = 0V 107 2.65 -21.1 -19.8 -0.2 2.8 -450 8 1.3 100 TYP MAX UNITS 17 400 100 25 430 150 mA mA µA 110 2.9 -21.7 -21.7 -0.05 10 113 10 -22.4 -22.4 0.1 400 100 400 Ω V mA mA V nA µA nA 10 12 pF 2.9 10 20 1.0 -650 20 170 3.0 20 50 1.2 -850 25 V mV mV V mA mA °C 1.5 160 10 1.7 250 15 V mV µA Note 1: Measuring each termination line while other 17 are low (0.5V). Note 2: Guaranteed by design. Not 100% tested in production. THERMAL DATA QP package: (see packaging section of UICC data book for more details on thermal performance) Thermal Resistance Junction to Leads, θjL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15°C/W Thermal Resistance Junction to Ambient, θja . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30°-40°C/W DWP package: Thermal Resistance Junction to Leads, θjL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18°C/W Thermal Resistance Junction to Ambient, θja . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33°-43°C/W J package: Thermal Resistance Junction to Leads, θjL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40°C/W Thermal Resistance Junction to Ambient, θja . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75°-85°C/W N package: Thermal Resistance Junction to Leads, θjL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50°C/W Thermal Resistance Junction to Ambient, θja . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95°-105°C/W Note: The above numbers for θjL are maximums for the limiting thermal resistance of the package in a standard mounting configuration. The θja numbers are meant to be guidelines for the thermal performance of the device/pc-board system. All of the above numbers assume no ambient airflow. 3 UC5601 UDG-94061 Typical SCSI Bus Configuration Using the UC5601 A Look at the Response of a SCSI-2 Cable Figure 1 shows a single line of a SCSI cable. The driver is an open colletor type which when asserted pulls low, and when negated the termination resistance serves as the pull-up. Figure 2 shows a worst case scenario of mid cable deassertion with a close proximity receiver. The voltage VSTEP is defined as: VSTEP = VOL +IO Z0 VOL = IO = Z0 = Driver Output Low Voltage Current from Receiving Terminator Cable Characteristic Impedance IO = UDG-94062 Figure 1. A Single Line of a SCSI Cable VREG − VOL 110 In the pursuit of higher data rates, sampling culd occur during this step portion, therefore it is important to ensure that the step is as high as possible to get the most noise margin. For this reason the UC5601 is trimmed so that the output current (IO) is as close as possible to the SCSI max current spec of 22.4mA. The Termination impedance is initially trimmed on the IC to 110 ohms typical, then the regulator voltage is trimmed for the highest output current to within 22.4mA. UDG-94063 Figure 2. A Typical Response of a SCSI Cable UNITRODE INTEGRATED CIRCUITS 7 CONTINENTAL BLVD. • MERRIMACK, NH 03054 TEL. (603) 424-2410 • FAX (603) 424 3460 4 PACKAGE OPTION ADDENDUM www.ti.com 18-Feb-2005 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty Lead/Ball Finish MSL Peak Temp (3) UC5601DWP ACTIVE SOIC DW 28 20 None CU SNPB Level-2-220C-1 YEAR UC5601DWPTR ACTIVE SOIC DW 28 1000 None CU SNPB Level-2-220C-1 YEAR UC5601DWPTRG4 ACTIVE SOIC DW 28 1000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR UC5601N ACTIVE PDIP N 24 UC5601QP ACTIVE PLCC FN UC5601QPTR ACTIVE PLCC FN 15 None CU SNPB Level-NA-NA-NA 28 37 None CU SNPB Level-2-220C-1 YEAR 28 750 None CU SNPB Level-2-220C-1 YEAR (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - May not be currently available - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. None: Not yet available Lead (Pb-Free). Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Green (RoHS & no Sb/Br): TI defines "Green" to mean "Pb-Free" and in addition, uses package materials that do not contain halogens, including bromine (Br) or antimony (Sb) above 0.1% of total product weight. (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDECindustry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Amplifiers amplifier.ti.com Audio www.ti.com/audio Data Converters dataconverter.ti.com Automotive www.ti.com/automotive DSP dsp.ti.com Broadband www.ti.com/broadband Interface interface.ti.com Digital Control www.ti.com/digitalcontrol Logic logic.ti.com Military www.ti.com/military Power Mgmt power.ti.com Optical Networking www.ti.com/opticalnetwork Microcontrollers microcontroller.ti.com Security www.ti.com/security Telephony www.ti.com/telephony Video & Imaging www.ti.com/video Wireless www.ti.com/wireless Mailing Address: Texas Instruments Post Office Box 655303 Dallas, Texas 75265 Copyright 2005, Texas Instruments Incorporated