UC560
27-LINE SCSI SOURCE/SINK REGULATOR
SLUS213B APRIL 1998 REVISED FEBRUARY 2001
1
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
D
SPI-2 and SPI-3 Compliant
D
2.85-V Regulated Output
Voltage with 1.4% Tolerance
D
Provides Current for up to
27 Lines of Active Termination
for SCSI Buses
D
750-mA Sourcing Current
for Termination
D
300-mA Sinking Current for
Active Negation Drivers
D
0.9-V Dropout Voltage Regulator
at 750 mA and 2.75 V Output
D
100- A Supply Current in
Disconnect Mode
D
Current Limit and Thermal Shutdown
Protection
D
Low Thermal Resistance Surface
Mount Package
description
The UC560 provides current for up to 27 lines of active termination for a SCSI (small computers systems
interface) parallel bus. The SCSI standard requires active termination at both ends of the cable. The UC560
is based on the UC5603 and UC5613 SCSI active terminators. It uses the voltage regulator and internal logic
circuits of those parts, but has no termination circuits. The UC560 provides greater source current-drive
capability compared to the UC5603 and UC5613.
The UC560 sink current maintains regulation with all active-negation drivers negated. It provides a disconnect
feature which disables the regulator to greatly reduce standby power. Internal circuit trimming is utilized for a
1.4% tolerance output voltage. Other features include thermal shutdown and current limit for short circuit
conditions.
The UC560 is available in low-thermal-resistance version of the industry standard 8-pin power SOIC.
AVAILABLE OPTIONS
TA
PACKAGED DEVICES
TA
SOIC (DP)
0
C to 70
C
UC560DP
The DP package is available taped and reeled. Add TR suffix to device type (e.g. UC560DPTR) to order
quantities of 3000 devices per reel.
Copyright
2000, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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.
simplified block diagram
8
4
1
THERMAL
SHUTDOWN
INTERNAL
BIAS
+
ENBL
+
2.85 V
REF
7
OUT
2.85 V
GND
6
3
2
GND
GND
GND
TRMPWR
(See Note A)
Note A: 4.0 V TO 6.0 V (4.75 V NOMIMAL)
UC560
27-LINE SCSI SOURCE/SINK REGULATOR
SLUS213B APRIL 1998 REVISED FEBRUARY 2001
2
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
1
2
3
4
8
7
6
5
OUT
HS/GND
HS/GND
ENBL
TERMPWR
HS/GND
HS/GND
N/C
DP PACKAGE
(TOP VIEW)
NOTE 1: For DP package, pins 2, 3, 6 and 7 are heat sinking pins. Pin 2 is the connect point for electrical ground.
NOTE 2: For all packages, N/C is no connection.
absolute maximum ratings over operating free-air temperature (unless otherwise noted)
Input voltage,
TERMPWR
7 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ENBL
0.3 V to TERMPWR + 0.3 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Regulator Output Current
1.4 A
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Dissipation
2.5 W
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage Temperature
65
C to 150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Junction Temperature
55
C to 150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead Temperature (Soldering, 10 seconds)
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.
Currents are positive into and negative out of the specified terminal. Consult Packaging Section of Interface Products Data Book (TI Literature
Number SLUD002) for thermal limitations and considerations of packages.
recommended operating conditions
MIN
MAX
UNIT
Input voltage, TERMPWR
4.0
6.0
V
Operating virtual junction temperature, TJ
W
0
70
C
It is not recommended that the device operate under conditions beyond those specified in this table for extended periods of time.
UC560
27-LINE SCSI SOURCE/SINK REGULATOR
SLUS213B APRIL 1998 REVISED FEBRUARY 2001
3
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range,
T
A
= 0
C to 70
C, TERMPWR = 4.75 V, ENBL = 0 V, C
OUT
= 4.7
F, C
TERMPWR
= 4.7
F, T
A
= T
J,
unless
otherwise specified.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Supply Current Section
TERMPWR supply current
No load
18
25
mA
TERMPWR supply current
IOUT = 700 mA
710
750
mA
Power down mode
ENBL = 2.0 V
100
140
A
Regulator Section
Regulator output voltage
25
C, No load
2.81
2.85
2.89
V
Load regulation
IOUT = 300 mA to 750 mA See Note 1
25
30
mV
Line regulation
TERMPWR = 4.0 V to 6.0 V
No load,
See Note 1
10
20
mV
Dropout voltage
IOUT = 750 mA
VOUT = 2.75 V
0.9
1.2
V
Short circuit current
VOUT = 0.0 V
1.3
0.85
A
Sinking current
VOUT = 3.5 V
500
600
mA
Sinking current
ENBL = 2.0 V
VOUT = 3.0 V
1
2
mA
Thermal shutdown
See Note 2
170
C
Thermal shutdown hysteresis
See Note 2
10
C
Shutdown Section
ENBL threshold
1.1
1.4
1.7
V
Threshold hysteresis
100
mV
ENBL output current
15
10
A
NOTES: 1. Tested at a constant junction temperature by low duty cycle pulse testing.
2. Ensured by design. Not production tested.
pin descriptions
ENBL: (Enable pin) The ENBL function is active low, and the pin sources 10
A (typical) when at ground and
TERMPWR is between 4 V and 6 V. The part goes into disable mode if ENBL is above 1.4 V (typical) , and returns
to enable mode when ENBL drops below 1.3 V typical. The part also greatly reduces TERMPWR current when
disabled (100
A typical).
GND: Ground pin.
OUT: (2.85-V regulated output voltage pin) The part is internally current limited for both sinking and sourcing
current to prevent damage. When the part is in disabled mode (ENBL 1.4 V typical), the output goes to 0 V with
no external supply source on OUT. The IC current sinks if there is an external supply voltage applied to OUT
when in disabled mode. For best perfomance, a 4.7-
F low-ESR capacitor is recommended.
TERMPWR: (Supply voltage pin) The pin should be decoupled with at least a 2.2-
F low-ESR output capacitor.
For best perfomance, a 4.7-
F low-ESR capacitor is recommended. Lead lengths should be kept at a minimum.
UC560
27-LINE SCSI SOURCE/SINK REGULATOR
SLUS213B APRIL 1998 REVISED FEBRUARY 2001
4
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
Figure 1
4
ENBL
1
OUT
TRMPWR
4.7
F
GND
8
2
4.7
F
110
TYPICAL SCSI BUS CONFIGURATION
(18 TERMINATION LINES)
UDG00075
Figure 2
4
ENBL
1
OUT
TRMPWR
4.7
F
GND
8
2
4.7
F
110
TYPICAL WIDE SCSI BUS CONFIGURATION
(27 TERMINATION LINES)
UDG00076
TYPICAL CHARACTERISTICS
Figure 3
OUTPUT VOLTAGE
vs
TEMPERATURE
0
2.80
2.82
2.84
2.86
2.88
2.90
20
40
60
80
Temperature C
No Load
Output V
o
ltage V
IOUT = 750 mA
IOUT = 300 mA
0
0.6
0.8
1.0
1.2
20
40
60
80
Temperature C
1.3
1.1
0.9
0.7
Figure 4
DROPOUT VOLTAGE
vs
TEMPERATURE
Dropout V
oltage (V
IN
V
OUT
) V
I
OUT
= 750 mA
V
OUT
= 2.75 V
UC560
27-LINE SCSI SOURCE/SINK REGULATOR
SLUS213B APRIL 1998 REVISED FEBRUARY 2001
5
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
Figure 5
LOAD REGULATION
vs
TEMPERATURE
0
20
22
28
20
40
60
80
Temperature C
30
26
24
Load Regulation mV
IOUT = 300 mA to 750 mA
Figure 6
LINE REGULATION
vs
TEMPERATURE
Line
Regulation mV
0
12
8
0
20
40
60
80
Temperature C
2
4
6
10
2
4
TRMPWR = 4 V to 6 V
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Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright
2001, Texas Instruments Incorporated
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