® REG5601 RE G5 60 1 RE G5 60 1 18-LINE SCSI ACTIVE TERMINATOR FEATURES DESCRIPTION ● COMPLIES WITH SCSI-2 SPECIFICATIONS ● INTERNAL 2.9V REGULATOR The REG5601 is an 18-line active terminator for SCSI-2 (Small Computer Systems Interface) circuitry. On-chip resistors and 2.9V regulator provide the prescribed 110Ω termination for low power dissipation and high speed data transmission. All line connections can be disconnected from the bus with a single logic control line to reduce standby power consumption. Output lines remain high impedance without power applied. Each line is individually clamped at ground to dissipate negative-going glitches. ● ON-CHIP TERMINATION RESISTORS ● DISCONNECT ALL TERMINATION RESISTORS WITH A SINGLE LOGIC COMMAND ● POWER-DOWN MODE: 150µA max ● LINE CAPACITANCE: 10pF typ ● CURRENT LIMIT AND THERMAL SHUTDOWN PROTECTION ● 28-Lead SOIC and SSOP PACKAGES The 2.9V regulator is current-limited and thermally protected. Regulated output is available for external circuitry. The REG5601 is available in 28-lead SOIC and finepitch SSOP packages and is specified for operation over the 0°C to 70°C temperature range. 2.9V Reg Out Termpwr Termpwr Thermal Shutdown Current Limit Clamp Switch Ground 110Ω 2.9V Disconnect 110Ω Signal Line 1 Signal Line 2 • • • (18 Lines) Switch Drive International Airport Industrial Park • Mailing Address: PO Box 11400 • Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd. • Tucson, AZ 85706 Tel: (520) 746-1111 • Twx: 910-952-1111 • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132 © 1994 Burr-Brown Corporation PDS-1216B Printed in U.S.A. August, 1995 SPECIFICATIONS TA = 0°C to +70°C, Termpwr = 4.75V, and Disconnect = 0V unless otherwise specified. REG5601U PARAMETERS CONDITIONS POWER SUPPLY Termpwr Supply Voltage Termpwr Supply Current MIN MAX MIN 5.25 25 430 150 4.0 14 385 100 115 107 2.65 19.8 19 –0.2 2.8 4.0 All Termination Lines = Open All VTERM = 0.5V Disconnect = Open (High) Power-Down Mode TERMINATION LINES Termination Impedance Output High Voltage Maximum Output Current ∆ITERM = 5mA to 15mA Termpwr = 4V(1) VTERM = 0.5V Termpwr = 4V, VTERM = 0.5V(1) ITERM = –30mA Disconnect = Open (High), Tempwr = 0V to 5.25V Disconnect = Open (High) Output Clamp Level Output Leakage Output Capacitance REGULATOR Regulator Output Voltage Line Regulation Load Regulation Drop-Out Voltage Short-Circuit Current Current Sink Thermal Shutdown Termpwr = 4V to 6V IREG = 0 to 400mA All VTERM = 0.5V, ∆VREG = 100mV VREG = 0V VREG = 3.5V DISCONNECT LOGIC INPUT Disconnect Threshold Threshold Hysterisis Input Current (Internal Pull-Up) 107 2.65 20.5 19.4 –0.2 110 2.8 21.7 21 –0.05 20 10 2.8 2.9 6 20 1.0 1350 11 170 3.0 20 50 1.2 1650 1.6 200 6 2.0 450 8 0.8 Disconnect = 0V TEMPERATURE RANGE Operating Storage θJL (junction to lead) REG5601E TYP 0 –40 22.4 22.4 0.1 400 450 8 0.8 15 70 150 TYP MAX UNIT 14 385 100 5.25 25 430 150 V mA mA µA 110 2.8 21.7 21 –0.05 20 10 115.5 Ω V mA mA V nA pF 2.9 6 20 1.0 1350 11 170 3.0 20 50 1.2 1650 V mV mV V mA mA °C 1.6 200 6 2.0 V mV µA 22.4 22.4 0.1 400 0 –40 20 15 70 150 20 °C °C °C/W NOTE: (1) Measurement of each termination line while the other 17 lines are held low (0.5V). ABSOLUTE MAXIMUM RATINGS CONNECTION DIAGRAM Top View Termpwr Voltage ................................................................................. +7V Signal Line Voltage ................................................................... 0V to +7V Regulator Output Current ................................................................. 1.65A Power Dissipation .............................................................................. 2.5W Operating Junction Temperature ................................... –40°C to +150°C Storage Temperature ..................................................... –40°C to +150°C SOIC SSOP Disconnect 1 28 GND Termination Line 1 2 27 Termination Line 18 Termination Line 2 3 26 Termination Line 17 Termination Line 3 4 25 Termination Line 16 Termination Line 4 5 24 Termination Line 15 Termination Line 5 6 23 Termination Line 14 MODEL (Thermal) GND 7 22 GND (Thermal) REG5601U REG5601E PACKAGE/ORDERING INFORMATION REG5601 (Thermal) GND 8 21 GND (Thermal) (Thermal) GND 9 20 GND (Thermal) Termination Line 6 10 19 Termination Line 13 Termination Line 7 11 18 Termination Line 12 Termination Line 8 12 17 Termination Line 11 Termination Line 9 13 16 Termination Line 10 Termpwr 14 15 Reg Out PACKAGE PACKAGE DRAWING NUMBER(1) Plastic 28-Lead SOIC Plastic 28-Lead SSOP 217 324 NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix D of Burr-Brown IC Data Book. ELECTROSTATIC DISCHARGE SENSITIVITY This integrated circuit can be damaged by ESD. Burr-Brown recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. NOTE: Pin 28 is electrical ground. Connect pins 7, 8, 9, 20, 21, 22 to large circuit trace for proper heat sinking. Connect to ground or leave open-circuit. The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant any BURR-BROWN product for use in life support devices and/or systems. ® REG5601 2 4V to 5.25V 4V to 5.25V 4.7µF Tantalum + 4.7µF Tantalum + 14 14 Termpwr 0 = Termination On 1 = Disconnect 1 28 Termpwr Regulator 15 Output REG5601 Disconnect Gnd T18 2.9V + 4.7µF Tantalum 4.7µF Tantalum T1 27 1 15 Regulator Disconnect Output REG5601 28 Gnd 2.9V 2 + T18 (18 Lines) To Controller Transceivers T1 27 SCSI Cable 0 = Termination On 1 = Disconnect 2 (18 Lines) To Controller Transceivers (18 Lines) FIGURE 1. Standard SCSI Termination Application. Thermal ground (leads 7, 8, 9, 20, 21, 22). Connect to circuit ground or leave open-circuit. TJ = TA + PD θJA PACKAGE CIRCUIT BOARD MATERIAL θJL JUNCTION TO LEAD + (°C/W) θBA BOARD TO AMBIENT (°C/W) θJA = JUNCTION TO AMBIENT (°C/W) SO-28 1-Layer(1) 3-Layer(2) Aluminum(3) 20 20 20 + + + 30 21 12 = = = 50 41 32 SSOP-28 1-Layer(1) 3-Layer(2) Aluminum(3) 20 20 20 + + + 36 23 13 = = = 56 43 33 NOTES: (1) Single-side layout on 0.062 inch FR4, 1 oz copper. (2) Three-layer layout on 0.062 inch FR4, 1 oz copper. (3) Aluminum 0.062 inch substrate, 0.003 insulation, one layer, 1 oz copper (Thermal Clad, Bergqueist Co.) FIGURE 2. Circuit Board Layout. A simple experiment will determine whether the actual circuit board layout is adequate (i.e., θBA is low enough) so that the maximum recommended junction temperature of the REG5601 will not be exceeded. The procedure uses the internal thermal shutdown feature of the REG5601 (at TJ ≈ 175°C) to determine when the junction is approximately 50°C above the maximum recommended junction temperature (TJ = 125°C). Operate the circuit with normal or other desired test electrical conditions. Increase the ambient temperature and determine the value at which thermal limit occurs (by sensing a sudden drop in VREG output). At this point TJ is approximately 175°C. If this occurs at an ambient temperature of more than 50°C above the system ambient temperature design goal, the TJ will not exceed 125°C under the same electrical conditions when the ambient temperature is at the system design goal value. The REG5601 has current limit and thermal shutdown that protect it from damage during output short-circuit or overload. The current limit is approximately 1350mA and thermal shutdown activates at a junction temperature of approximately 175°C. For good reliability, the junction temperature should not exceed 125°C. Any tendency to activate the thermal shutdown during normal operation is an indication of inadequate heat sinking and/or excessive power dissipation. Heat is dissipated primarily by conduction through the leads to circuit board traces. It is important to connect the six thermal ground leads (7, 8, 9, 20, 21, 22) to a large circuit trace—see Figure 2. Measured values of thermal resistance for various circuit board materials are shown. These are approximate values. Variations in circuit board pattern, mounting techniques, air flow, proximity to other circuit boards and heat sources will affect thermal performance. ® 3 REG5601