UltraMAX
TM
LX5245/5246/5247
9 - L
I N E
LV D S C S I T
E R M I N A T O R
T
H E
I
N F I N I T E
P
O W E R
O F
I
N N O VA T I O N
P
R E L I M I N A R Y
D
A T A
S
H E E T
DESCRIPTION
The LX5245/5246/5247 ICs are Low Volt-
age Differential (LVD) Terminators
de-
signed to comply with the LVD termination
specification in the SPI-4 document. The
LX5245/5246/5247 are designed specifically
for LVD applications. Because the LX5245/
5246/5247 support only LVD, they have lower
output capacitance than multimode termina-
tors such as the LX5240.
The LX5245/5246/5247 Utilize
Linfinity’s UltraMAX Technology
which
delivers the ultimate in SCSI bus performance
while saving component cost and board area.
Elimination of the external capacitors also
mitigates the need for a lengthy capacitor
selection process. The individual high band-
width drivers also maximize channel sepa-
ration and reduces channel-to-channel noise
and cross talk. The high-bandwidth
UltraMAX architecture insures ULTRA-2 per-
formance, while providing a clear migration
path to ULTRA-3 and beyond.
When The LX5245/5246/5247 Are
Enabled, The Differential Sense
(DIFFSENSE) Pin Supplies A Voltage
Between 1.2V And 1.4V.
In application,
the terminator DIFFSENSE output is con-
nected to the system DIFFSENSE line. If
there are no single ended or HVD devices
attached to the system the LVD output will
be enabled. If the DIFFSENSE line is LOW,
indicating a single ended device, the LX5245/
5246/5247 output will be HiZ. If the
DIFFSENSE line is HIGH, indicating a high
voltage differential device the LX5245/5246/
5247 output will be HiZ.
The LX5245/5246/5247 ICs Have A TTL
Compatible DISCONNECT Pin.
The
LX5245/47 is active LOW and the LX5246
is active HIGH. During sleep mode, power
dissipation is reduced to a meager 5µA, while
also placing all outputs in a HI Z state. Also
during sleep mode, the DIFFSENSE function
is disabled and is placed in a HI Z state.
K E Y F E AT U R E S
s
2.5pF Typical Disabled Output
Capacitance
s
Fast Response, No External Capacitors
Required
s
5µA Supply Current In Disconnect Mode
s
20mA Supply Current During Normal
Operation
s
Logic Command Disconnects All
Termination Lines
s
Diffsense Line Driver
s
Current Limit And Thermal Protection
s
Compliant with SPI-2 (Ultra2), SPI-3 (Ultra160),
and SPI-4 (Ultra320),
s
Mention 5249 as LVD only terminator
with pinout compatable with industry
standard multi-mode terminators
s
Pin compatable with unitrode UCC5640
NOTE:
For current data & package dimensions, visit our web site:
http://www.linfinity.com.
PRODUCT HIGHLIGHT
B
U S
V
O LTA G E 1
V
OD
V
OD
= V
(-)
- V
(+)
, Logic = 0
V
(+)
100mV
0V
NEGATED
V
CM
V
(-)
-100mV
LX5245/46/47
LX5245/46/47
PA C K A G E O R D E R I N F O
T
A
(°C)
PW
Plastic TSSOP
24-pin
28-PIN
LX5245CPW
LX5246CPW
0 to 70
Note: All surface-mount packages are available in Tape & Reel.
Append the letter "T" to part number. (i.e. LX5245CPWT)
Copyright © 2000
Rev. 0.7 4/8/2002
L
IN
F
INITY
M
ICROELECTRONICS
I
NC
.
11861 W
ESTERN
A
VENUE
, G
ARDEN
G
ROVE
, CA. 92841, 714-898-8121, F
AX
: 714-893-2570
1
PRODUCT DATABOOK 1996/1997
LX5245/5246/5247
9 - L
I N E
LV D S C S I T
E R M I N A T O R
P
R E L I M I N A R Y
UltraMAX
D
A T A
S
H E E T
PACKAGE PIN OUTS
A B S O L U T E M A X I M U M R AT I N G S
(Note 1)
TermPwr Voltage .............................................................................................. +6.5V
Signal Line Voltage ................................................................................... 0V to 6.5V
Differential Voltage ................................................................................... 0V to 6.5V
Operating Junction Temperature
Plastic (PW Package) ................................................................................... 150°C
Storage Temperature Range .............................................................. -65°C to 150°C
Lead Temperature (Soldering, 10 seconds) .................................................... 300°C
Note 1. Exceeding these ratings could cause damage to the device. All voltages are with
respect to Ground. Currents are positive into, negative out of the specified
terminal.
LX5245/46 CPW
N.C.
1+
1-
2+
2-
3+
3-
4+
4-
DIFFB
DIFFSENSE
GND
1
2
3
4
5
6
7
8
9
10
1
12
1
24
23
22
21
20
19
18
17
16
15
14
13
V
TERM
9-
9+
8-
8+
7-
7+
6-
6+
5-
5+
DISC
T H E R M A L D ATA
PW PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θ
JA
100°C/W
24L PW PACKAGE
(Top View)
("N.C." = No Internal Connections)
Junction Temperature Calculation: T
J
= T
A
+ (P
D
x
θ
JA
).
The
θ
JA
numbers are guidelines for the thermal performance of the device/pc-board
system. All of the above assume no ambient airflow.
DIFFSENSE / P
OWER
U
P
/ P
OWER
D
OWN
F
UNCTION
T
ABLE
LX5245/LX5247
DISCONNECT
L
L
L
H
Open
LX5246
DISCONNECT
H
H
H
L
Open
DIFFSENSE
L < 0.5V
0.7V to 1.9V
H > 2.4V
X
X
Outputs
Status
Type
Disable
Enable
Disable
Disable
Disable
HiZ
LVD
HiZ
HiZ
HiZ
Quiescent
Current
2mA
21mA
2mA
10µA
10µA
2
Copyright © 2000
Rev. 0.7 4/8/2002
PRODUCT DATABOOK 1996/1997
UltraMAX
9 - L
I N E
LV D S C S I T
E R M I N A T O R
P
R E L I M I N A R Y
LX5245/5246/5247
D
A T A
S
H E E T
(Note 2)
R E C O M M E N D E D O P E R AT I N G C O N D I T I O N S
Parameter
Termpwr Voltage
Signal Line Voltage
Disconnect Input Voltage
Operating Junction Temperature Range
LX5245 / 5246/5247
Note 2. Range over which the device is functional.
Symbol
V
TERM
Recommended Operating Conditions
Min.
Typ.
Max.
3.0
0
0
0
5.25
5.0
V
TERM
70
Units
V
V
V
°C
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply over the operating ambient temperature range of 0°C
≤
T
A
≤
70°C. TermPwr = 3.3V,
DISCONNECT: LX5245/47 = L, LX5246 = H. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to
the ambient temperature.)
Parameter
LVD Terminator Section
TermPwr Supply Current
Common Mode Voltage
Offset Voltage (fail safe bias voltage)
Differential Terminator Impedance
Common Mode Impedance
Output Capacitance
Output Leakage
Mode Change Delay
Symbol
Test Conditions
LX5245 / 5246
Min. Typ.
Max.
21
5
1.125 1.25
100 112
100 105
100 200
2.5
0
1
100 150
1.2
5.0
1.3
Units
LVD I
CC
V
OM
V
OS
Z
D
Z
CM
C
o
I
Leak
t
DF
V
DIFF
I
DIFF
I
SINK(DIFF)
I
LEAK(DIFF)
V
TH
I
IH
All term lines = Open
DISCONNECT: LX5245/47 = H, LX5246 = L
Open circuit between - and + (see Note 3)
V
OD
= -1V to 1V
0V to 2.5V
DISCONNECT: LX5245/47 = H, LX5246 = L
DISCONNECT: LX5245/47 = H, LX5246 = L, V
LINE
= 0 to 4V, T
A
=25°C
DISCONNECT: LX5245/47 = H, LX5246 = L, V
TERM
= 0V, V
LINE
= 2.7V
DIFFSENSE = 1.4V to 0V
25
mA
10
µA
1.375 V
125 mV
110
Ω
300
Ω
pF
2
µA
µA
ms
1.4
15.0
200
10
2.0
10
10
V
mA
µA
µA
V
µA
µA
DIFFSENSE Section
DIFFSENSE Output Voltage
DIFFSENSE Output Source Current
DIFFSENSE Sink Current
DIFFSENSE Output Leakage
DIFFSENSE = 0V
V
IN
= 2.75V
DISCONNECT: LX5245/47 = H, LX5246 = L, T
A
= 25°C
DISCONNECT Section
DISCONNECT Threshold
Input Current
Note 3. Open circuit failsafe voltage.
0.8
DISCONNECT: LX5245/47 = 0V
DISCONNECT: LX5246 = 3.3V
Copyright © 2000
Rev. 0.7 4/8/2002
3
PRODUCT DATABOOK 1996/1997
LX5245/5246/5247
9 - L
I N E
LV D S C S I T
E R M I N A T O R
P
R E L I M I N A R Y
UltraMAX
D
A T A
S
H E E T
BLOCK DIAGRAM
Power ON
V
TERMPWR
DISC
Internal V
REF
1.30V
1.07mA
1 of 9
HVD
LVD
2D(-)
52.5
SE
LVD (-)
LVD
1.25V
2cm
200
2D(+)
52.5
HVD
LVD
LVD (+)
10mA
SE
DIFFSENSE
1.07mA
HVD
LATCH
LVD
DIFF B
Window
Comp.
SE
Power ON
Power ON
& Mode
Change
Delay
FIGURE 1
— LX5245 Block Diagram
4
Copyright © 2000
Rev. 0.7 4/8/2002
PRODUCT DATABOOK 1996/1997
UltraMAX
9 - L
I N E
LV D S C S I T
E R M I N A T O R
P
R E L I M I N A R Y
LX5245/5246/5247
D
A T A
S
H E E T
FUNCTIONAL PIN DESCRIPTION
Pin
Designator
1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-1
V
TERM
Description
Negative signal termination lines.
Power supply pin for terminator. Connect to SCSI bus TERMPWR. Must be decoupled by one 4.7µF
low-ESR capacitor for every three terminator devices. It is absolutely necessary to connect this pin to
the decoupling capacitor through a very low impedance (big traces on PCB). Keeping distances very
short from the decoupling capacitors to the V
TERM
pin is also critical. The value of the decoupling
capacitor is somewhat layout dependant and some applications may benefit from high-frequency
decoupling with 0.1µF capacitors right at V
TERM
pin.
Enables / disables terminator. See Power Down Function Table for logic levels per device.
Terminator ground pin. Connect to ground.
Used to drive DIFFSENS output 3V @ 10 mt. Usually connected through a 20kOhm resistor to DIFF B
pin.
Used to detect the SCSI BUS mode (LUD, HUD, SE)
1+, 2+, 3+, 4+, 5+, 6+, 7+, 8+, 9+ Positive signal termination lines.
DISC1
GND1
DIFFSENSE1
DIFFB1
Copyright © 2000
Rev. 0.7 4/8/2002
5
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