UC5604 9-Line Low Capacitance SCSI Active Terminator FEATURES DESCRIPTION • Complies with SCSI, SCSI-2 Standards • 9pF Channel Capacitance during Disconnect The UC5604 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 • −300mA Sourcing Current for Termination • +40mA Sinking Current for Active Negation • Logic Command Disconnects all Termination Lines • Trimmed Termination Current to 7% • Trimmed Impedance to 7% • Current Limit and Thermal Shutdown Protection The UC5604 provides a disconnect feature which, when opened or driven high, will disconnect all terminating resistors and disable the regulator, greatly reducing standby power. The output channels remain high impedance even without Termpwr applied. The UC5604 is pin-for-pin compatible with its predecessor, the UC5603 - 9 line Active Terminator. The only functional difference between the UC5604 and UC5603 is the absence of the negative clamps. Parametrically, the UC5604 has a 7% tolerance on impedance and current compared to a 3% tolerance on the UC5603 and the sink current is reduced from 300mA to 40mA. Custom power packages are utilized to allow normal operation at full power conditions (1.2 watts). Internal circuit trimming is utilized, first to trim the impedance to a 7% tolerance, and then most importantly, to trim the output current to a 7% tolerance, as close to the max SCSI spec as possible, which maximizes noise margin in 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-94064 Circuit Design Patented 3/97 UC5604 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. ZIP-16 (Top View) Z Package SOIC-16 (Top View) DP Package * DP package pin 5 serves as signal ground; pins 4, 12, 13 serve as heatsink/ground. Note: Drawings are not to scale. 2 UC5604 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 VLINE = 0.5V, TRMPWR = 4V (Note 1) Output Clamp Level Output Leakage ILINE = -30mA 0°C < TJ < 70°C TJ = 25°C TJ = 25°C 0°C < TJ < 70°C TJ = 25°C 0°C < TJ < 70°C 97 2.55 2.6 -19.5 -18.5 -18.0 -17.0 -0.2 DISCNCT = 4V TRMPWR = 0V to 5.25V VLINE = 0 to 4V REG = 0V VLINE = 5.25V TRMPWR = 0V to 5.25V, REG = Open VLINE = 0V to 5.25V DISCNCT = Open (Note 2) Output Capacitance Regulator Section Regulator Output Voltage Regulator Output Voltage All Termination Lines = 5V Line Regulation TRMPWR = 4V to 6V Load Regulation IREG = +100mA to -100mA Drop Out Voltage All Termination Lines = 0.5V Short Circuit Current VREG = 0V Sinking Current Capability VREG = 3.5V Thermal Shutdown Thermal Shutdown Hysteresis Disconnect Section Disconnect Threshold Threshold Hysteresis Input Current DISCNCT = 0V Note 1: Measuring each termination line while other 8 are low (0.5V). Note 2: Guaranteed by design. Not 100% tested in production. 2.5 2.55 -200 20 1.1 TYP MAX UNITS 14 200 100 20 220 150 mA mA µA 110 10 129 3.2 3.1 -22.4 -22.4 -22.4 -22.4 0.1 400 100 400 Ohms V V mA mA mA mA V nA µA nA 9 12 pF 2.9 2.9 10 20 1.0 -400 40 170 10 3.2 3.1 20 50 1.2 -600 V V mV mV V mA mA °C °C 1.4 100 150 1.7 V mV µA 2.9 -21.9 -21.9 -21.9 -21.9 -0.05 10 200 APPLICATION INFORMATION UDG-94065 Figure 1: Typical SCSI Bus Configurations Utilizing 2 UC5604 Devices 3 UC5604 APPLICATION INFORMATION (cont.) UDG-94066 Figure 2: Typical Wide SCSI Bus Configurations Utilizing 3 UC5604 Devices. UNITRODE CORPORATION 7 CONTINENTAL BLVD. • MERRIMACK, NH 03054 TEL. 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