• Complies with SCSI, SCSI-2 and
SPI-2 Standards
• 3pF Channel Capacitance during
Disconnect
• 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 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.
The UC5613 provides a disconnect feature which, when opened or driven
high, disconnects all terminating resistors and disables the regulator
greatly redu cing stan dby power. The output c hannels 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 compatibl e with its predeces sor, the UC5603 - 9
line Active Terminator. The only functiona l differ ence be twee n the UC5613
and UC5603 is the absence of the negative clamps. Parametrically, the
UC5613 has a 5 % tol er ance o n im peda nce 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 a s possi ble to th e 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.
UC5613
9-Line Low Capacitance SCSI Active Terminator
FEATURES DESCRIPTION
BLOCK DIAGRAM
Circuit Design Patented
3/97
UDG-94003-1
ABSOLUTE MAXIMUM RATINGS
Termpwr Vo ltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +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
RECOMMENDED OPERATING CONDITIONS
Termpwr Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8V to 5.25V
Signal Line Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to +5V
Disconnect Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to Termpwr
CONNECTION DIAGRAMS
DIL-16 (Top View)
N or J Package
UC5613
* DP packag e pi n 5 se rves as signal ground; pins 4, 12, 13
serve as heatsink/ground.
* 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
TSSOP-24 (To p View)
PWP Package
Note: Drawings are not to scale.
Unless otherwise sp ec ified all voltages are with respect to G r ou nd . C urre nt s are pos itive into, negative out of the specified terminal.
Consult Packaging Section of Unitrode Integrated Circuits databook for thermal limitations and consid era ti on s of pac ka ges.
2
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Supply Current Section
Termpwr Supply Current All termination lines = Open 17 23 mA
All termination li ne s = 0. 5V 200 225 mA
Power Down Mode DISCNCT = Open 100 150 µA
Output Section (Termina tor Li ne s)
Terminator Impedance ∆I
LINE
= -5mA to -15mA 104.5 110 115.5 Ohms
Output High Voltage TRMPWR = 4V (Note 1) 2.7 2.9 V
Max Output Cur r e nt V
LINE
= 0.5V TJ = 25°C -20.3 -21.5 -22.4 mA
0°C < T
J
< 70°C -19.8 -21.5 -22.4 mA
Max Output Cur r e nt V
LINE
= 0.5V, TRMPWR = 4V (Note 1) TJ = 25°C -19.5 -21.5 -22.4 mA
0°C < T
J
< 70°C -19.0 -21.5 -22.4 mA
V
LINE
= 0.2V, TRMPWR = 4V to 5.25V 0°C < TJ < 70°C -21.6 -24.0 -25.4 mA
Output Leakage
DISCNCT = 4V
TRMPWR = 0V to 5.25V
REG = 0V
V
LINE
= 0 to 4V 10 400 nA
V
LINE
= 5.25V 100 µA
TRMPWR = 0V to 5.25V, REG = Open
V
LINE
= 0V to 5.25V
10 400 nA
Output Capacitance DISCNCT = Open, DP Package (Note 2) 3 4.5 pF
Regulator Section
Regulator Output Voltage 2.8 2.9 3 V
Regulator Output Voltage All Termination Lines = 5V 2.8 2.9 3 V
Line Regulation TRMPWR = 4V to 6V 10 20 mV
Load Regulation I
REG
= +100mA to -100mA 20 50 mV
Drop Out Voltage All Termination Lines = 0.5V 0.7 1 V
Short Circuit Current V
REG
= 0V -200 -400 -600 mA
Sinking Current Capability V
REG
= 3.5V 200 400 600 mA
Thermal Shutdown 170 °C
Thermal Shutdown Hysteresis 10 °C
Disconnect Section
Disconnect Threshold 1.3 1.5 1.7 V
Threshold Hysteresis 100 160 250 mV
Input Current DISCNCT = 0V 10 15 µA
ELECTRICAL CHARACTERISTICS
Unless otherwise st at ed, th ese sp ecif icat io ns app ly for TA = 0°C to 70°C.
TRMPWR = 4.75V, DISCNCT = 0V. TA = TJ.
UC5613
Note 1: Measuring each terminatio n li ne wh il e ot he r 8 are lo w (0.5 V).
Note 2: Guaranteed by design. Not 10 0% tes te d in prod uc ti on .
Figure 1: Typical SCSI Bus Configurations Utilizing 2 UC5613 Devices
APPLICATION INFORMATION
UDG-94007-1
3
Figure 2: Typical Wide SCSI Bus Configurations Util iz in g 3 UC56 13 Devi ce s.
UC5613
UDG-94008-1
UNITRODE CORPORATI ON
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TEL. (603) 424- 24 10 • FAX (603) 424-3460
APPLICATION INFORMATION (cont.)
4
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