FEATURES
Complies with SCSI and SCSI-2
Standards
8pF Channel Capacitance during
Disconnect
SCSI Plug and Play, Dual Low
Disconnect, Logic Low Command
Disconnects All Termination Lines
Meets SCSI Hot Plugging Capability
-
650mA Sourcing Current for
Termination
+200mA Sinking Current for Active
Negation
200
A Supply Current in Disconnect
Mode
Trimmed Termination Current to 7%
Trimmed Impedance to 7%
Provides Active Termination for 18
Lines
UC5607
Plug and Play, 18-Line SCSI Active Terminator
BLOCK DIAGRAM
7/98
UDG-94124
Connect
Connect
Connect
Disc
DISCNCT1
1
0
1
0
DISCNCT2
0
1
1
0
DESCRIPTION
The UC5607 provides 18 lines of active termination for a SCSI (Small
Computer Systems Interface) parallel bus. The SCSI standard recom-
mends active termination at both ends of the cable segment.
The UC5607 provides a low disconnect feature which will disconnect all
terminating resistors, and will disable the regulator, greatly reducing
standby power. The output channels remain high impedance even without
Termpwr applied.
The UC5607 terminator is specially designed with two disconnect pins for
full SCSI Plug and Play (PnP) applications.
Custom power packages are utilized to allow normal operation at full
power conditions (2 Watts).
Internal circuit trimming is utilized, first to trim the impedance to a 7% tol-
erance, and then most importantly, to trim the output current to a 7% toler-
ance, 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 28 pin wide body SOIC, and 28 pin PLCC, as well as 24 pin DIP.
Circuit Design Patented
2
UC5607
ABSOLUTE MAXIMUM RATINGS
Termpwr Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7V
Signal Line Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to +7V
Regulator Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . 1A
Storage Temperature . . . . . . . . . . . . . . . . . . .
-
65C to +150C
Operating Temperature . . . . . . . . . . . . . . . . .
-
55C to +150C
Lead Temperature (Soldering, 10 Sec.). . . . . . . . . . . . . +300C
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 Cir-
cuits 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
* QP package pins 12 - 18 serve as both heatsink and signal
ground.
** DISCNCT2 is internally tied to ground.
* DWP package pin 8 serves as signal ground; pins 7, 8, 9, 20,
21, 22 serve as heatsink/ground.
Note: Drawings are not to scale.
PLCC-28 (Top View)
QP Package
SOIC-28 (Top View)
DWP Package
DIL-24 (Top View)
N or J Package
3
UC5607
Figure 1: Typical SCSI Bus Configuration Utilizing UC5607 Device
APPLICATION INFORMATION
UDG-98136
UNITRODE CORPORATION
7 CONTINENTAL BLVD. MERRIMACK, NH 03054
TEL. (603) 424-2410
_
FAX (603) 424-3460
ELECTRICAL CHARACTERISTICS
Unless otherwise stated, these specifications apply for T
A
= 0C to 70C.
TRMPWR = 4.75V, DISCNCT1 = DISCNCT2 = 2.2V. T
A
= T
J
.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
S
Supply Current Section
Termpwr Supply Current
All termination lines = Open
30
45
mA
All termination lines = 0.5V
420
470
mA
Power Down Mode
DISCNCT1 = DISCNCT2 = 0V
300
500
m
A
Output Section (Terminator Lines)
Terminator Impedance
D
I
LINE
= 5mA to 15mA
T
J
= 25C
102
110
118
Ohms
0C < T
J
< 70C
97
110
129
Ohms
Output High Voltage
V
TRMPWR
= 4V (Note 1)
T
J
= 25
C
2.6
2.9
3.1
V
0C < T
J
< 70C
2.55
2.9
3.2
V
Max Output Current
V
LINE
= 0.5V
T
J
= 25C
19.5
21.9
22.4
mA
0C < T
J
< 70C
18.5
21.9
22.4
mA
Max Output Current
V
LINE
= 0.5V, TRMPWR = 4V (Note 1)
T
J
= 25C
18.0
21.9
22.4
mA
0C < T
J
< 70C
17.0
21.9
22.4
mA
Output Leakage
DISCNCT1 = DISCNCT2 = 0V, TRMPWR = 0V to 5.25V
10
400
nA
Output Capacitance
DISCNCT1 = DISCNCT2 = 0V (Note 2)
8
10
pF
Regulator Section
Regulator Output Voltage
All Termination Lines = 5V
T
J
= 25C
2.7
2.9
3.1
V
0C < T
J
< 70C
2.55
2.9
3.2
V
Line Regulation
TRMPWR = 4V to 6V
10
20
mV
Load Regulation
I
REG
= +100mA to 100mA
20
50
mV
Note 1: Measuring each termination line while other 17 are low (0.5V).
Note 2: Guaranteed by design. Not 100% tested in production.
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pertaining to warranty, patent infringement, and limitation of liability.
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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
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In order to minimize risks associated with the customer's applications, adequate design and operating
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Copyright
1999, Texas Instruments Incorporated
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