UltraMAX
T
H E
™
LX5245 / 5246
D
A T A
9-L
INE
LVD SCSI T
ERMINATOR
I
N F I N I T E
P
O W E R
O F
I
N N O V A T I O N
P
R E L I M I N A R Y
S
H E E T
IMPORTANT:
For the most current data, consult
MICROSEMI’s
website:
http://www.microsemi.com
V
(+)
V
CM
V
(-)
Copyright
©
2000
Rev. 0.8a,2005-03-02
NO
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PRODUCT HIGHLIGHT
100mV
NEGATED
0V
-100mV
DESCRIPTION
When The LX5245/5246 Are Enabled, The
The LX5245/5246 ICs are Low Voltage
Differential (LVD) Terminators
designed to
Differential Sense (DIFFSENSE) Pin Supplies
comply with the LVD termination specification in
A Voltage Between 1.2V And 1.4V.
In
application, the terminator DIFFSENSE output is
the SPI-4 document. The LX5245/5246 are
connected to the system DIFFSENSE line. If
designed specifically for LVD applications.
there are no single ended or HVD devices
Because the LX5245/ 5246 support only LVD,
attached to the system the LVD output will be
they have lower output capacitance than
enabled. If the DIFFSENSE line is LOW,
multimode terminators such as the LX5241.
The LX5245/5246 Utilize Linfinity’s UltraMAX
indicating a single ended device, the LX5245/
5246 output will be HiZ. If the DIFFSENSE line
Technology
which delivers the ultimate in SCSI
bus performance while saving component cost and is HIGH, indicating a high voltage differential
board area. Elimination of the external capacitors device the LX5245/5246 output will be HiZ.
also mitigates the need for a lengthy capacitor
The LX5245/5246 ICs Have A TTL
Compatible DISCONNECT Pin.
The LX5245
selection process. The individual high bandwidth
is active LOW and the LX5246 is active HIGH.
drivers also maximize channel separation and
During sleep mode, power dissipation is reduced
reduces channel-to-channel noise and cross talk.
to a meager 5µA, while also placing all outputs in
The high-bandwidth UltraMAX architecture
insures ULTRA-2 performance, while providing a a HI Z state. Also during sleep mode, the
DIFFSENSE function is disabled and is placed in
clear migration path to ULTRA-3 and beyond.
a HI Z state.
KEY FEATURES
2.5pF Typical Disabled Output
Capacitance
Fast Response, No External
Capacitors Required
5µA Supply Current In
Disconnect Mode
20mA Supply Current During
Normal Operation
Logic Command Disconnects All
Termination Lines
Diffsense Line Driver
Current Limit And Thermal
Protection
Compliant With SPI-2 (Ultra2),
SPI-3 (Ultra160),
Mention 5249 as LVD Only
Terminator With Pinout
Compatible With Industry
Standard Multi-mode
Terminators
Pin Compatible With Unitrode
UCC5640
V
OD
= V
(-)
- V
(+)
, Logic =0
LX5245/46
LX5245/46
PACKAGE ORDER INFO
Plastic TSSOP
PW
24-Pin
T
A
(°C)
RoHS / Pb-free
Transition DC: 0442
0 to 70
LX5245CPW
LX5246CPW
Note: Available in Tape & Reel. Append the letters “TR” to
the part number. (i.e. LX5245CPW-TR)
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
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)
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N.C.
1+
1-
2+
2-
3+
3-
4+
4-
DIFFB
DIFFSENSE
GND
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
Peak Package Solder Reflow Temperature (40 second maximum exp.)....260°C(+0, -5)
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
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:
24L PW PACKAGE
(Top View)
("N.C." = No Internal Connections)
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θ
JA
RoHS / Pb-free 100% Matte Tin Lead Finish
100°C/W
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
LX5246
DISCONNECT
H
H
H
L
Open
DIFFSENSE
Outputs
Status
Type
HiZ
LVD
HiZ
HiZ
HiZ
LX5245
DISCONNECT
L
L
L
H
Open
Quiescent
Current
2mA
21mA
2mA
10µA
10µA
L < 0.5V
0.7V to 1.9V
H > 2.4V
X
X
Disable
Enable
Disable
Disable
Disable
2
Copyright © 2000
Rev. 0.8a
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
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
Symbol
V
TERM
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Recommended Operating Conditions
Min.
Typ.
Max.
3.0
0
0
0
5.25
5.0
V
TERM
70
Units
V
V
V
°C
Termpwr Voltage
Signal Line Voltage
Disconnect Input Voltage
Operating Junction Temperature Range
LX5245 / 5246
Note 2. Range over which the device is functional.
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 = L, LX5246 = H. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to
the ambient temperature.)
Parameter
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 Terminator Section
TermPwr Supply Current
LVD I
CC
V
OM
V
OS
Z
D
Z
CM
C
o
I
Leak
t
DF
All term lines = Open
DISCONNECT: LX5245 = H, LX5246 = L
Common Mode Voltage
Offset Voltage (fail safe bias voltage)
Differential Terminator Impedance
Common Mode Impedance
Output Capacitance
Output Leakage
Mode Change Delay
Open circuit between - and + (see Note 3)
V
OD
= -1V to 1V
0V to 2.5V
DISCONNECT: LX5245 = H, LX5246 = L
DISCONNECT: LX5245 = H, LX5246 = L, V
LINE
= 0 to 4V, T
A
=25°C
DISCONNECT: LX5245 = 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
V
DIFF
I
DIFF
I
SINK(DIFF)
I
LEAK(DIFF)
V
TH
I
IH
DIFFSENSE = 0V
V
IN
= 2.75V
DISCONNECT: LX5245 = H, LX5246 = L, T
A
= 25°C
DISCONNECT Section
DISCONNECT Threshold
Input Current
0.8
DISCONNECT: LX5245 = 0V
DISCONNECT: LX5246 = 3.3V
Note 3. Open circuit failsafe voltage.
Copyright © 2000
Rev. 0.8a
3
PRODUCT DATABOOK 1996/1997
LX5245/5246
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
V
TERMPWR
DISC
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Power ON
Internal V
REF
1.30V
1.07mA
1 of 9
HVD
LVD
SE
LVD (-)
LVD
1.25V
2cm
200
2D(-)
52.5
2D(+)
52.5
HVD
LVD
SE
LVD (+)
10mA
DIFFSENSE
1.07mA
HVD
LATCH
DIFF B
Window
Comp.
SE
LVD
Power ON
Power ON
& Mode
Change
Delay
FIGURE 1
— LX5245 Block Diagram
4
Copyright © 2000
Rev. 0.8a
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
D
A T A
S
H E E T
FUNCTIONAL PIN DESCRIPTION
1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-
V
TERM
1+, 2+, 3+, 4+, 5+, 6+, 7+, 8+, 9+ Positive signal termination lines.
DISC
GND
DIFFB
DIFFSENSE
Copyright © 2000
Rev. 0.8a
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Description
Negative signal termination lines.
Terminator ground pin. Connect to ground.
Differential sense pin connected to system DIFFSENSE line.
Pin
Designator
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.
Used to detect the SCSI BUS mode (LVD, HVD, SE). Should be connected to 4.7µF to ground
and 50k Ohm resistor to DIFFSENSE pin (See Figure 3).
5
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