UC5613 9-Line Low Capacitance SCSI Active Terminator FEATURES DESCRIPTION • Complies with SCSI, SCSI-2 and SPI-2 Standards • 3pF Channel Capacitance during Disconnect The UC5613 provides 9 lines of active termination for a SCSI (Small Computer Systems Interface) parallel bus. The SCSI standard recommends active termination at both ends of the cable segment. • 100µA Supply Current in Disconnect Mode • Meets SCSI Hot Plugging Capability • −400mA Sourcing Current for Termination • +400mA Sinking Current for Active Negation • Logic Command Disconnects all Termination Lines • Trimmed Termination Current to 5% • Trimmed Impedance to 5% • Current Limit and Thermal Shutdown Protection The UC5613 provides a disconnect feature which, when opened or driven high, disconnects all terminating resistors and disables the regulator greatly reducing standby power. The output channels remain high impedance even without Termpwr applied. A low channel capacitance of 3pF allows units at interim points of the bus to have little or no effect on the signal integrity. The UC5613 is pin-for-pin compatible with its predecessor, the UC5603 - 9 line Active Terminator. The only functional difference between the UC5613 and UC5603 is the absence of the negative clamps. Parametrically, the UC5613 has a 5% tolerance on impedance and current compared to a 3% tolerance on the UC5603. Custom power packages are utilized to allow normal operation at full power (1.2 watts). Internal circuit trimming is utilized, first to trim the impedance to a 5% tolerance; then, the output current is trimmed to a 5% tolerance. The output current trim is set as close as possible to the maximum value of the SCSI specification which maximizes the noise margin for fast SCSI operation. Other features include thermal shutdown and current limit. This device is offered in low thermal resistance versions of the industry standard 16 pin narrow body SOIC, 16 pin ZIP (zig-zag in line package), and 24 pin TSSOP. BLOCK DIAGRAM UDG-94003-1 3/97 Circuit Design Patented UC5613 ABSOLUTE MAXIMUM RATINGS Termpwr Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7V Signal Line Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to +7V Regulator Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5A 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. RECOMMENDED OPERATING CONDITIONS Termpwr Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8V to 5.25V Signal Line Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to +5V Disconnect Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to Termpwr CONNECTION DIAGRAMS TSSOP-24 (Top View) PWP Package DIL-16 (Top View) N or J Package * PWP package pin 5 serves as signal ground; pins 6, 7, 8, 9, 17, 18, 19, and 20 serve as heatsink/ground. SOIC-16 (Top View) DP Package ZIP-16 (Top View) Z Package * DP package pin 5 serves as signal ground; pins 4, 12, 13 serve as heatsink/ground. Note: Drawings are not to scale. 2 UC5613 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 (Terminator Lines) Terminator Impedance ∆ILINE = -5mA to -15mA Output High Voltage TRMPWR = 4V (Note 1) Max Output Current VLINE = 0.5V Max Output Current Output Leakage Output Capacitance Regulator Section Regulator Output Voltage Regulator Output Voltage Line Regulation Load Regulation Drop Out Voltage Short Circuit Current Sinking Current Capability Thermal Shutdown Thermal Shutdown Hysteresis Disconnect Section Disconnect Threshold Threshold Hysteresis Input Current 104.5 2.7 TJ = 25°C -20.3 0°C < TJ < 70°C -19.8 TJ = 25°C -19.5 VLINE = 0.5V, TRMPWR = 4V (Note 1) 0°C < TJ < 70°C -19.0 0°C < TJ < 70°C -21.6 VLINE = 0.2V, TRMPWR = 4V to 5.25V TRMPWR = 0V to 5.25V V LINE = 0 to 4V DISCNCT = 4V REG = 0V VLINE = 5.25V TRMPWR = 0V to 5.25V, REG = Open VLINE = 0V to 5.25V DISCNCT = Open, DP Package (Note 2) All Termination Lines = 5V TRMPWR = 4V to 6V IREG = +100mA to -100mA All Termination Lines = 0.5V VREG = 0V VREG = 3.5V 2.8 2.8 -200 200 1.3 100 DISCNCT = 0V TYP MAX UNITS 17 200 100 23 225 150 mA mA µA 110 2.9 -21.5 -21.5 -21.5 -21.5 -24.0 10 115.5 10 -22.4 -22.4 -22.4 -22.4 -25.4 400 100 400 Ohms V mA mA mA mA mA nA µA nA 3 4.5 pF 2.9 2.9 10 20 0.7 -400 400 170 10 3 3 20 50 1 -600 600 V V mV mV V mA mA °C °C 1.5 160 10 1.7 250 15 V mV µA Note 1: Measuring each termination line while other 8 are low (0.5V). Note 2: Guaranteed by design. Not 100% tested in production. APPLICATION INFORMATION UDG-94007-1 Figure 1: Typical SCSI Bus Configurations Utilizing 2 UC5613 Devices 3 UC5613 APPLICATION INFORMATION (cont.) UDG-94008-1 Figure 2: Typical Wide SCSI Bus Configurations Utilizing 3 UC5613 Devices. UNITRODE CORPORATION 7 CONTINENTAL BLVD. • MERRIMACK, NH 03054 TEL. (603) 424-2410 • FAX (603) 424-3460 4 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. 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