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SLUS195A – MARCH 1997 – REVISED OCTOBER 2000
Complies with SCSI, SCSI–2 and SPI–2
Standards
6-pF Channel Capacitance during
Disconnect
100-µA Supply Current in Disconnect Mode
Meets SCSI Hot Plugging
–400-mA Sourcing Current for Termination
+400-mA 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
description
The UC5603 provides 9 lines of active termination for a SCSI (Small Computers 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 6 pF 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 5 V, while the regulator remains at its nominal value, reduced channel capacitance to 6 pF
typical, and as with the UC5601, custom power packages are utilized to allow normal operation at full power
conditions (1.2 watts).
functional block diagram
UDG-94049
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright 2000, Texas Instruments Incorporated
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SLUS195A – MARCH 1997 – REVISED OCTOBER 2000
description (continued)
Internal circuit trimming is utilized, first to trim the impedance to a 3% tolerance, 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 external circuitry from latch-up, thermal
shutdown and current limit.
This device is offered in low thermal resistance versions of the industry standard 16 pin narrow body SOIC, and
24 pin TSSOP.
connection diagrams
N PACKAGE
(TOP VIEW)
LINE7
LINE8
LINE9
N/C
SGND
DISCNCT
LINE1
LINE2
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
PWP PACKAGE
(TOP VIEW)
LINE6
LINE5
REG
N/C
N/C
TRMPWR
LINE4
LINE3
LINE7
LINE8
LINE9
N/C
SGND
GND*
GND*
GND*
GND*
DISCNCT
LINE1
LINE2
DP PACKAGE
(TOP VIEW)
LINE7
LINE8
LINE9
GND*
SGND*
DISCNCT
LINE1
LINE2
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
LINE6
LINE5
REG
GND*
GND*
TRMPWR
LINE4
LINE3
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
* PWP package pin 5 serves as signal ground; pins 6,
7, 8, 9, 17, 18, 19, and 20 serve as heatsink/ground.
* DP package pin 5 serves as signal ground; pins 4,
12, 13 serve as heatsink/ground.
ORDERING INFORMATION
Packaged Devices
TA = TJ
DIL -16(N)
SOIC-16 (DP)
TSSOP-24
(PWP)
0°C to 70°C
UC5603N
UCUC5603DP
UCUC5603PWP
† DP (SOIC–16) and PWP (TSSOP–24) packages are available taped and reeled. Add TR
suffix to device type (e.g. UC5603PWPTR) to order quantities of 2000 devices per reel.
2
LINE6
LINE5
REG
N/C
GND*
GND*
GND*
GND*
N/C
TRMPR
LINE4
LINE3
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absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Termpwr voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Signal line voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to 7 V
Regulator output current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 A
Storage temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C
Operating temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –55°C to 150°C
Lead temperature (soldering, 10 sec.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
‡ 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8 V to 5.25 V
Signal line voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V to 5 V
Disconnect input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V to Termpwr
electrical characteristics, these specifications apply for TA = 0°C to 70°C. TRMPWR = 4.75 V
DISCNCT = 0 V, TA = TJ, (unless otherwise stated)
supply current section
PARAMETER
Termpwr supply current
Power down mode
TEST CONDITIONS
MIN
TYP
MAX
UNITS
All termination lines = Open
12
18
mA
All termination lines = 0.5 V
200
220
mA
DISCNCT = Open
100
150
µA
output section (terminator lines)
PARAMETER
Terminator impedance
TEST CONDITIONS
∆ILINE = –5 mA to –15 mA
VTRMPWR = 4 V,
MIN
TYP
MAX
Ω
107
110
2.7
2.9
–21.1
–21.9
–22.4
mA
VLINE = 0.5
05V
TJ = 25°C
0°C < TJ < 70°C
–20.5
–21.9
–22.4
mA
TRMPWR = 4 V,
–20.3
–21.9
–22.4
mA
output
Max out
ut current
VLINE = 0.5 V,
See Note 1
TJ = 25°C
0°C < TJ < 70°C
–19.8
–21.9
–22.4
mA
VLINE = 0.2 V,
ILINE = –30 mA
TRMPWR = 4.0 V to 5.25 V
0°C < TJ < 70°C
–22.0
–24.0
–25.4
mA
Output clamp level
–0.2
–0.05
0.1
10
400
nA
100
µA
10
400
nA
6
8
pF
Output high voltage
Max output current
Output leakage
See Note 1
TRMPWR = 0 V to 5.25,
VREG = 0 V
DISCNCT = 4 V
TRMPWR = 0 V to 5.25 V,
VLINE = 0 V to 5.25 V
Output capacitance
DISCNCT = Open
See Note 2
VLINE = 0 to 4 V
VLINE = 5.25 V
REG = Open
DP Package
113
UNITS
V
V
NOTES: 1. Measuring each termination line while other 8 are low (0.5 V).
2. Ensured by design. Not production tested.
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SLUS195A – MARCH 1997 – REVISED OCTOBER 2000
regulator section
PARAMETER
TEST CONDITIONS
Regulator output voltage
UNITS
2.9
3
2.9
3
V
TRMPWR = 4 V to 6 V
10
20
mV
IREG = 100 mA to –100 mA
All termination lines = 0.5 V
20
50
mV
0.7
1
V
–200
–400
–600
mA
200
400
600
mA
Line regulation
Load regulation
Sinking current capability
MAX
2.8
All termination lines = 5 V
Short circuit current
TYP
2.8
Regulator output voltage
Drop out voltage
MIN
VREG = 0 V
VREG = 3.5 V
Thermal shutdown
Thermal shutdown hysteresis
V
170
°C
10
°C
disconnect section
PARAMETER
TEST CONDITIONS
Disconnect threshold
Threshold hysteresis
Input current
DISCNCT = 0 V
MIN
TYP
MAX
UNITS
1.3
1.5
1.7
V
100
160
250
mV
10
15
mA
APPLICATION INFORMATION
UDG-94050
Figure 1. Typical Wide SCSI Bus Configurations Utilizing 1 UC5601 and 1 UC5603 Device
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APPLICATION INFORMATION
UDG-94051
Figure 2. Typical Wide SCSI Bus Configurations Utilizing 3 UC5603 Devices
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5
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Copyright 2000, Texas Instruments Incorporated