SSC SS7519

SS7519
Multi-mode SCSI Terminator
FEATURES
!" Meets SCSI-1, SCSI-2, Ultra3 and
Single-Ended resistor will maintain 110Ω ± 5%.
For LVD termination, the SS7519
Ultra320 Standards.
!" Auto-selectable Multimode single-ended
or Low Voltage Differential termination.
!" Current limit and thermal shutdown
integrates two current sources with nine
accuracy resistor strings. This architecture yields
a 105Ω ±5% differential and 226Ω ±10%
common mode impedance. A fail-safe bias of
protection.
!" Ground driver integrated for
110mV is sustained when no drivers are
single-ended operation
connected to the SCSI bus. If the SS7519
!" Compatible with active-negation drivers.
detects a HVD SCSI device on the bus, all the
signals will be set to a high impedance state.
DESCRIPTION
The SS7519 multimode SCSI terminator is
both a single-ended and a low voltage
differential terminator that meets the
specifications of SCSI Parallel Interface (SPI-4).
The SS7519 also provides backward
compatibility to the SCSI-1, SCSI-2 and
Single-Ended specifications. The Multimode
terminator contains all the functions required to
terminate and auto detect for SCSI devices
VRFF
1
28
TPWR
RIP
2
27
TPWR
RIN
3
26
R9N
R2P
4
25
R9P
R2N
5
24
R8N
HS GND
6
23
R8P
R3P
7
22
HS GND
R3N
8
21
R7N
without hardware fluctuation. Auto-Selectable is
achieved by using voltage detection on the
DIFFSENSE signal. The SS7519 senses the
DIFFSENSE line while sourcing the
DIFFSENSE signal with LVD levels. The
DIFFSENSE line being grounded indicates that
R4P
9
20
R7P
R4N
10
19
R6N
R5P
11
18
R6P
R5N
12
17
DIFF_CAP
ISO
13
16
DIFFSENSE
GND
14
15
M/S
one or more SE devices are attached on the bus.
The SS7519 switches to the termination mode
SS7519 - TSSOP28
that is appropriate for the bus based on the value
of the DIFFSENSE input voltage.
For the Single-Ended termination, the active
terminator will pull RXN to 2.85V and RXP to a
hard ground. The SS7519 can sink 22mA
per line as required by the SCSI specification. The
Rev.2.01 6/06/2003
www.SiliconStandard.com
1 of 5
SS7519
PIN DESCRIPTION
PIN
27,28
SYMBOL
TPWR
DESCRIPTION
4.0V to 5.75V power input pin. Connect to SCSI bus power line. A
4.7µF capacitor and a 0.1µF high frequency capacitor are recommended
between TPWR and ground.
1
Reference Voltage. Must be decoupled with a 4.7µF capacitor to
VREF
ground as shown in Figure 1.
6,22
Heat Sink Ground. These should be connected to large area PC board
HS GND
14
ground trace in order to increase the power dissipation capability.
GND
2,4,7,9,11,18 RxP
Termination lines. These lines switch to hard ground in SE mode and
20,23,25
are the positive lines for LVD mode. All lines are in high impedance
when HVD is detected.
3,5,8,10,12
Termination lines. These lines switch to the active lines in SE mode
RxN
19,21,24,26
and are the negative lines for LVD mode. All lines are in high
impedance when HVD is detected.
13
Isolate pin. This pin used to shut down the terminator if the terminator
ISO
is not connected at the end of the bus. Connecting the pin to ground will
activate the terminator in normal operation. The terminator will be
disabled when the pin is in high state. An internal pull-down resistor
assures that the SS7519 will operate as normal if the ISO pin is left
floating.
15
Mode select pin. When pull high, master mode will enable the
M/S
DIFFSEN drive SCSI bus. The DIFFSENSE driver is off when this pin
is connected to ground.
16
DIFFSENSE Mode Sense pin. This signal will drive 1.3V to the SCSI bus during the
Master mode in order to detect which type of device is connected to
the SCSI bus. On power up, the SS7519 will try to deliver LVD
level to the DIFFSENSE line. If only LVD SCSI devices are on the
bus, the DIFFSENSE signal will be successfully driven to 1.3V and the
terminator will configure the system for LVD operation. If any SE
device is on the bus, it will present a grounding level to the
DIFFSENSE line. This will cause the SS7519 to configure into SE
operation. The SS7519 will go into shutdown mode if DIFFSENSE
detects a high voltage level.
17
DIFFSENSE CAPACITOR. This pin should be connected to a 0.1uF
DIF_CAP
capacitor to ground and 20KΩ resistor to SCSI bus DIFFSENSE line
for DIFFSEN filter.
RECOMMENDED OPERATING CONDITIONS
PARAMETER
Tpwr Voltage
Operating Temperature
Lead Temperature
(Soldering 10 seconds)
Rev.2.01 6/06/2003
SYMBOL
Vterm
Top
Tsod
MIN
4.0
0
TYP.
300
www.SiliconStandard.com
MAX
5.75
70
UNITS
V
℃
℃
2 of 5
SS7519
DC CHARACTERISTICS:
PARAMETER
TPWR Current
Input Leakage Current
High
Input Leakage Current
Low
Output Current High
Vout = 2.4 V
Output Current Low
Vout = 0.4V
DIFFSEN Output Voltage
DIFFSEN Source Current
DIFFSEN Sink Current
DIFFSEN SE Voltage
Range
DIFFSEN LVD Voltage
Range
DIFFSEN HVD Voltage
Range
SYMBOL
Itpwr
Iih
MIN
TYP
35
MAX
UNITS
mA
uA
1.0
uA
0
Iil
Ioh
0
mA
Iol
4.0
mA
Vov
Isc
Isi
Vse
1.2
20
-0.3
1.4
15
200
0.5
V
mA
uA
V
Vlvd
0.7
1.9
V
Vhvd
2.4
Vtpwr+0.3 V
5
Single Ended Characteristics
PARAMETER
SE Termination Resistance
SE Voltage Reference
SE Output Current
SYMBOL
Rse
Vref
Ioc
MIN
104.5
2.70
TYP
110
MAX
115.5
3.00
25.4
UNITS
Ω
V
mA
SYMBOL
Rd
MIN
100
TYP
MAX
110
UNITS
Ω
Rc
110
226
300
Ω
Vdb
100
125
mV
Vcb
1.125
1.375
V
LVD Characteristics
PARAMETER
Differential Mode
Termination Resistance
Common Mode
Termination Resistance
Differential Mode Bias
All lines open
Common Mode Bias
REGULATOR Characteristics
PARAMETER
Source Current
SYMBOL
Isour
MIN
TYP
200
Sink Current
Isink
100
200
(0℃
℃ to 70℃
℃)
MAX
UNITS
230
mA
Vout=0.2v
mA
NOTE: Unless otherwise specified, these specifications apply over the operating ambient
temperature range from 0℃
℃ to 70℃
℃.
Rev.2.01 6/06/2003
www.SiliconStandard.com
3 of 5
SS7519
Application
Schematic
TPWR
27,28
15
13
TPWR
M/S
ISO
TPWR
M/S
ISO
CONTROL
SS7519
DIFFSEN
16
1
16
15
13
DIFFSEN
1
17
20k
20k
0.1uF 4.7uF
27,28
TPWR
15
M/S 13
ISO
TPWR
M/S
ISO
DATA
SS7519
SS7519
17
VREF DIF_CAP 17
DIF_CAP VREF
1
1
4.7uF
27,28
15
13
4.7uF
27,28
TPWR
M/S
ISO
TPWR
15
M/S 13
ISO
DATA
SS7519
1
4.7uF
Rev.2.01 6/06/2003
15
13
DIF_CAP VREF
17
4.7uF 0.1uF
27,28
SS7519
VREF DIF_CAP
27,28
TPWR
SS7519
VREF
VREF
DIF_CAP
17
17
1
DIF_CAP
Figure 1.
www.SiliconStandard.com
4.7uF
4 of 5
SS7519
Package Dimensions
TSSOP-28
28
H
E
15
θ
L
b
1
Detail F
14
L1
D
e
Seating Plane
TSSOP-28
SYMBOLS
A
A1
A2
b
C
D
H
E
e
L
L1
y
θ
A
See Detail F
A1
A2
C
12°
(4X)
D y
DIMENSIONS IN
MILIMETERS
MIN
NOM
MAX
__________
__________
1.20
__________
0.05
0.15
0.80
1.00
1.05
__________
0.19
0.30
__________
0.09
0.20
9.60
9.70
9.80
__________
__________
6.40
4.30
4.40
4.50
__________
__________
0.65
0.45
0.60
0.75
__________
__________
1.00
__________
__________
0.076
__________
0°
8°
DIMENSIONS IN INCHES
MIN
NOM
__________
__________
0.002
0.031
0.007
0.004
0.378
__________
0.039
__________
__________
__________
0.382
0.252
0.173
0.026
0.024
0.039
__________
__________
0°
__________
__________
0.169
__________
0.018
MAX
0.047
0.006
0.041
0.012
0.008
0.385
__________
0.177
__________
0.030
__________
0.003
8°
Information furnished by Silicon Standard Corporation is believed to be accurate and reliable. However, Silicon Standard Corporation makes no
guarantee or warranty, express or implied, as to the reliability, accuracy, timeliness or completeness of such information and assumes no
responsibility for its use, or for infringement of any patent or other intellectual property rights of third parties that may result from its
use. Silicon Standard reserves the right to make changes as it deems necessary to any products described herein for any reason, including
without limitation enhancement in reliability, functionality or design. No license is granted, whether expressly or by implication, in relation to
the use of any products described herein or to the use of any information provided herein, under any patent or other intellectual property rights of
Silicon Standard Corporation or any third parties.
Rev.2.01 6/06/2003
www.SiliconStandard.com
5 of 5