Complies with SCSI, SCSI-2 and
SPI-2 Standards
6pF Channel Capacitance during
Disconnect
100
A Supply Current in
Disconnect Mode
Meets SCSI Hot Plugging
-400mA Sourcing Current for
Termination
+400mA Sinking Current for
Active Negation Drivers
Logic Command Disconnects all
Termination Lines
Trimmed Termination Current to
3%
Trimmed Impedance to 3%
Negative Clamping on all Signal
Lines
Current Limit and Thermal
Shutdown Protection
The UC5603 provides 9 lines of active termination for a SCSI (Small Comput-
ers Systems Interface) parallel bus. The SCSI standard recommends active
termination at both ends of the cable segment.
The UC5603 provides a disconnect feature which, when opened or driven
high, will disconnect 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 6pF allows units
at interim points of the bus to have little to no effect on the signal integrity.
Functionally the UC5603 is similar to its predecessor, the UC5601 - 18 line
Active Terminator. Several electrical enhancements were incorporated in the
UC5603, such as a sink/source regulator output stage to accommodate all
signal lines at +5V, while the regulator remains at its nominal value, reduced
channel capacitance to 6pF typical, and as with the UC5601, 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 3% toler-
ance, and then most importantly, to trim the output current to a 3% tolerance,
as close to the max SCSI spec as possible, which maximizes noise margin in
fast SCSI operation.
Other features include negative clamping on all signal lines to protect exter-
nal circuitry from latch-up, thermal shutdown and current limit.
This device is offered in low thermal resistance versions of the industry stand-
ard 16 pin narrow body SOIC, 16 pin ZIP (zig-zag in line package) and 24 pin
TSSOP.
UC5603
9-Line SCSI Active Terminator
FEATURES DESCRIPTION
BLOCK DIAGRAM
Circuit Design Patented
3/97
UDG-94049
DIL-16 (Top View)
N or J Package
* DP package pin 5 serves as signal ground; pins 4, 12, 13
serve as heatsink/ground.
ZIP-16 (Top View)
Z Package
SOIC-16 (Top View)
DP Package
TSSOP-24 (Top View)
PWP Package
Note: Drawings are not to scale.
UC5603
Termpwr Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7V
Signal Line Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to +7V
Regulator Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5A
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
-
65C to +150C
Operating Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
-
55C to +150C
Lead Temperature (Soldering, 10 Sec.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300C
ABSOLUTE MAXIMUM RATINGS
Termpwr Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8V to 5.25V
Signal Line Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to +5V
Disconnect Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to Termpwr
RECOMMENDED OPERATING CONDITIONS
CONNECTION DIAGRAMS
Unless otherwise specified all voltages are with respect to Ground. Currents are posi-
tive into, negative out of the specified terminal.
Consult Packaging Section of Unitrode Integrated Circuits databook for thermal limita-
tions and considerations of packages.
* PWP package pin 5 serves as signal ground; pins 6, 7, 8, 9,
17, 18, 19, and 20 serve as heatsink/ground.
2
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Supply Current Section
Termpwr Supply Current
All termination lines = Open
12
18
mA
All termination lines = 0.5V
200
220
mA
Power Down Mode
DISCNCT = Open
100
150
A
Output Section (Terminator Lines)
Terminator Impedance
I
LINE
= -5mA to -15mA
107
110
113
Ohms
Output High Voltage
V
TRMPWR
= 4V (Note 1)
2.7
2.9
V
Max Output Current
V
LINE
= 0.5V
T
J
= 25
C
-21.1
-21.9
-22.4
mA
0
C < T
J
< 70
C
-20.5
-21.9
-22.4
mA
Max Output Current
V
LINE
= 0.5V, TRMPWR = 4V (Note 1)
T
J
= 25
C
-20.3
-21.9
-22.4
mA
0
C < T
J
< 70
C
-19.8
-21.9
-22.4
mA
V
LINE
= 0.2V, TRMPWR = 4.0V to 5.25V
0
C < T
J
< 70
C 22.0
24.0
25.4
mA
Output Clamp Level
I
LINE
= -30mA
-0.2
-0.05
0.1
V
Output Leakage
DISCNCT = 4V
TRMPWR = 0V to 5.25V
REG = 0V
V
LINE
= 0 to 4V
10
400
nA
V
LINE
= 5.25V
100
A
TRMPWR = 0V to 5.25V, REG = Open
V
LINE
= 0V to 5.25V
10
400
nA
Output Capacitance
DISCNCT = Open (Note 2) (DP Package)
6
8
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
ELECTRICAL CHARACTERISTICS
Unless otherwise stated, these specifications apply for T
A
= 0C to 70C.
TRMPWR = 4.75V DISCNCT = 0V. T
A
= T
J
.
UC5603
Note 1: Measuring each termination line while other 8 are low (0.5V).
Note 2: Guaranteed by design. Not 100% tested in production.
3
Figure 1:
Typical Wide SCSI Bus Configurations Utilizing 1 UC5601 and 1 UC5603 Device
Figure 2:
Typical Wide SCSI Bus Configurations Utilizing 3 UC5603 Devices.
UC5603
APPLICATION INFORMATION
UDG-94051
UDG-94050
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.
TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in
accordance with TI's standard warranty. Testing and other quality control techniques are utilized to the extent
TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily
performed, except those mandated by government requirements.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF
DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE ("CRITICAL
APPLICATIONS"). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR
WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER
CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO
BE FULLY AT THE CUSTOMER'S RISK.
In order to minimize risks associated with the customer's applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other
intellectual property right of TI covering or relating to any combination, machine, or process in which such
semiconductor products or services might be or are used. TI's publication of information regarding any third
party's products or services does not constitute TI's approval, warranty or endorsement thereof.
Copyright
1999, Texas Instruments Incorporated
PDF 
ZIP