Microsemi LX5255CPW-TR 9-line lvd scsi terminator Datasheet

LX5255
®
TM
9-Line LVD SCSI Terminator
P RODUCTION
DATA SHEET
KEY FEATURES
DESCRIPTION
ƒ Compliant with SPI-2 (Ultra2),
SPI-3 (Ultra160), and SPI-4
(Ultra320)
ƒ 2.5pF Maximum Disabled Output
Capacitance
ƒ Fast Response, No External
Capacitors Required
ƒ 5µA Supply Current in Disconnect
Mode
ƒ 30mA Supply During Normal
Operation
ƒ Logic Command Disconnects All
Termination Lines
ƒ DIFSENS Line Driver
ƒ Current Limit and Thermal
Protection
ƒ Pin Compatible With Unitrode
UCC5640
supplies a voltage between 1.2V and
1.4V. In application, the terminator
DIFFB input is connected to the system
DIFSENS line. If there are no single
ended or High Voltage Differential
(HVD) devices attached to the system,
the LVD output will be enabled. If the
DIFSENS line is LOW, indicating a
single ended device, the LX5255 output
will be HiZ. If the DIFSENS line is
HIGH, indicating a HVD device, the
LX5255 output will be HiZ.
The LX5255 has a TTL compatible
sleep/disable mode. Applying a logic
HIGH to the DISC pin puts the LX5255
in sleep mode. During sleep mode,
power dissipation is reduced to a meager
5μA while also placing all outputs and
the DIFSENS function in a HiZ state.
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The LX5255 is a Low Voltage
Differential
(LVD)
terminator
designed to comply with the LVD
termination specification in the SPI-4
document. The LX5255 is specifically
designed for LVD only applications.
Because the LX5255 supports only
LVD, it has lower output capacitance
than multimode terminators such as
the LX5250.
The LX5255 utilizes an industry
standard LVD architecture. The
individual high bandwidth drivers
maximize channel separation, reduce
channel-to-channel noise and cross
talk to insure Ultra320 performance.
When the LX5255 is enabled, the
Differential Sense (DIFSENS) pin
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
TYPICAL APPLICATION
-
L X 5255
-
+
+
L X 5255
LX5255
LX5255 Typical Application
PACKAGE ORDER INFO
Plastic TSSOP
PW
24-Pin
TA (°C)
RoHS Compliant / Pb-free
Transition DC: 0442
0 to 70
LX5255CPW
Note: Available in Tape & Reel. Append the letters “TR” to the
part number. (i.e. LX5255CPW-TR)
Copyright © 2000
Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
LX5255
®
TM
9-Line LVD SCSI Terminator
P RODUCTION
ABSOLUTE MAXIMUM RATINGS
PACKAGE PIN OUT
NC
1+
12+
23+
34+
4DIFFB
DIFSENS
GND
Exceeding these ratings could cause damage to the device. All voltages are with respect to
Ground. Currents are positive into, negative out of specified terminal.
THERMAL DATA
PW
1
24
2
23
3
22
4
21
5
20
6
19
7
18
8
17
9
16
10
15
11
14
12
13
VTERM
99+
88+
77+
66+
55+
DISC
PW PACKAGE
(Top View)
NC – No Internal Connection
24L TSSOP
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Term Power (VTERM)............................................................................................-0.3V to 7V
Signal Line Voltage .............................................................................................-0.3V to 7V
Differential Voltage .............................................................................................-0.3V to 7V
Operating Junction Temperature.................................................................................. 150°C
Storage Temperature Range........................................................................... -65°C to 150°C
Peak Package Solder Reflow Temperature (40 second maximum exposure) . 260°C (+0, -5)
Note:
DATA SHEET
RoHS / Pb-free 100% Matte Tin Lead Finish
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
100°C/W
Junction Temperature Calculation: TJ = TA + (PD x θJA).
The θJA numbers are guidelines for the thermal performance of the device/pc-board
system. All of the above assume no ambient airflow. θJA can vary significantly
depending on mounting technique. (See Application Notes Section: Thermal
considerations)
DIFFB/POWER UP/POWER DOWN FUNCTION TABLE
DISC
Outputs
DIFFB
Status
Type
Quiescent
Current
L
L < 0.5V
Disable
HI-Z
8mA
L
0.7V to 1.9V
Enable
LVD
30mA
L
H > 2.4V
Disable
HI-Z
8mA
H or Open
X
Disable
HI-Z
10µA
RECOMMENDED MAX OPERATING CONDITIONS
Parameter
Symbol
VTERM
LX5255
Typ
2.7
Max
Units
5.25
V
V
Signal Line Voltage
0
5.0
Disconnect Input Voltage
0
VTERM
V
0
70
°C
Operating Junction Temperature
Copyright © 2000
Rev. 1.1, 2006-02-27
TJ
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
PACKAGE DATA
VTerm
Min
Page 2
LX5255
®
TM
9-Line LVD SCSI Terminator
P RODUCTION
DATA SHEET
`
`
LVD Terminator Section
ICC
Common Mode Voltage
VCM
Offset Voltage (Note 1)
VOS
Open circuit between (-) and (+) terminals
Differential Terminator Impedance
ZD
VOUT Differential = -1V to +1V
Common Mode Impedance
ZCM
0.5V to 2V
Output Capacitance (Note 2)
CO
DISCONNECT > 2.0V
Mode Change Delay
tDF
DIFSENS = 1.4V to 0V
30
5
1.25
35
20
1.375
mA
µA
V
100
112
125
mV
100
105
110
Ω
110
150
190
Ω
3
pF
100
115
300
ms
1.2
1.3
1.4
V
1.125
DIFSENS Section
DIFSENS Output Voltage
DIFSENS Output Source Current
DIFSENS Sink Current
`
All term lines open
DISCONNECT > 2.0V
VTerm Supply Current
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ELECTRICAL CHARACTERISTICS
Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C ≤ TA ≤ 70°C, VTerm = 3.3V,
and DISCONNECT = 0V.
LX5255
Parameter
Symbol
Test Conditions
Units
Min
Typ
Max
VDIFF
IDIFF
DIFSENS = 0V
5
15
mA
ISINK(DIFF)
VTERM = 2.75V
20
200
µA
0.8
2.0
V
10
µA
Disconnect Section
Disconnect Threshold
VTH
Input Current
IIH
DISCONNECT = 0V
Note 1: Open Circuit failsafe voltage.
Note 2: Guaranteed by design.
ELECTRICALS
Copyright © 2000
Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 3
LX5255
®
TM
9-Line LVD SCSI Terminator
P RODUCTION
DATA SHEET
VTERM
DISC
24
13
1 of 9
Lines
1.07 mA
DISC
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BLOCK DIAGRAM
HVD
LVD
3
LVD(-)
2
LVD(+)
SE
52.5
150
HVD
52.5
LVD
1.25V
SE
1.07 mA
10mA
I-Limited
1.3V
Source
DIFSENS
DIFFB
11
10
12
GND
DISC
-
SE
Window
Comp.
+
HVD
LATCH
LVD
POWER
ON
&
MODE
DELAY
Figure 1 – LX5255CPW Block Diagram
FUNCTIONAL PIN DESCRIPTION
PIN NAME
DESCRIPTION
1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-
Negative signal termination lines for LVD mode.
1+, 2+, 3+, 4+, 5+, 6+, 7+, 8+, 9+
Positive signal termination lines for LVD mode.
VTERM
absolutely necessary to connect this pin to the decoupling capacitor through a very low
impedance (big traces to PCB). Keeping distances very short from the decoupling
capacitors is somewhat layout dependent and some applications may benefit from high
frequency decoupling with 0.1µF capacitors at VTERM pin.
DISC
Enables/Disables terminator. See Power Down Function Table for logic levels.
GND
Terminator ground pin. Connect to ground.
DIFSENS
DIFFB
Differential sense pin connected to system DIFFSENS line. Drives the SCSI bus
DIFSENS line to 1.3V.
Used to detect the SCSI bus mode (SE, LVD or HVD). Should be connected to a 4.7uF
capacitor to GND, and a 50KΩ resistor to the DIFFSENS pin (see Figure 2 on page 5).
5
Copyright © 2000
Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 4
PACKAGE DATA
Power supply pin for terminator. Connect to SCSI bus VTERM. Must be
decoupled by one 4.7µF low-ESR capacitor for every three terminator devices. It is
LX5255
®
TM
9-Line LVD SCSI Terminator
P RODUCTION
DATA SHEET
PERIPHERAL
HOST
TERMPOWER
11+
VTERM
11+
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APPLICATION
TERMPOWER
VTERM
Data Lines (9)
LX5255
DISCONNECT
99+
99+
LX5255
GND
GND
DIFSENS
DIFFB
DIFSENS
DIFFB
NC*
50k
Pin 1
4.7uF
4.7uF
DISCONNECT
DISC
DISC
VTERM
50k
4.7uF
4.7uF
11+
11+
NC*
Pin 1
4.7uF
VTERM
4.7uF
Data Lines (9)
LX5255
99+
99+
LX5255
DISC
DISC
GND
GND
DIFSENS
DIFSENS
DIFFB
DIFFB
NC*
Pin 1
4.7uF
NC*
Pin 1
11+
VTERM
11+
4.7uF
VTERM
Control Lines (9)
LX5255
99+
99+
LX5255
DISC
DISC
GND
GND
DIFSENS
DIFSENS
Pin 1
NC*
Pin 1
APPLICATIONS
4.7uF
DIFFB
DIFFB
NC*
4.7uF
* The capacitor on Pin 1 can be placed on the LX5255PCW to be pin compatible with other devices. This capacitor is not required.
Figure 2 – Suggested Microsemi LX5255 Universal Application Schematic
Copyright © 2000
Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 5
LX5255
®
TM
9-Line LVD SCSI Terminator
P RODUCTION
DATA SHEET
PW
WWW . Microsemi .C OM
MECHANICAL DRAWINGS
24-Pin Thin Small Shrink Outline (TSSOP)
3 21
P
E
F
D
A H
SEATING PLANE
Dim
G
MILLIMETERS
MIN
MAX
0.85
0.95
0.19
0.30
0.09
0.20
7.70
7.90
4.30
4.50
0.65 BSC
0.05
0.15
–
1.10
0.50
0.75
0°
8°
6.25
6.55
–
0.10
L
C
M
INCHES
MIN
MAX
0.033
0.037
0.007
0.012
0.0035 0.008
0.303
0.311
0.169
0.177
0.025 BSC
0.002
0.005
–
.0433
0.020
0.030
0°
8°
0.246
0.256
–
0.004
* Lead Coplanarity
Note:
1. Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006”) on any side. Lead dimension shall not include
solder coverage.
Copyright © 2000
Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 6
MECHANICALS
A
B
C
D
E
F
G
H
L
M
P
*LC
B
LX5255
TM
®
9-Line LVD SCSI Terminator
P RODUCTION
DATA SHEET
WWW . Microsemi .C OM
NOTES
NOTES
PRODUCTION DATA – Information contained in this document is proprietary to
Microsemi and is current as of publication date. This document may not be modified in
any way without the express written consent of Microsemi. Product processing does not
necessarily include testing of all parameters. Microsemi reserves the right to change the
configuration and performance of the product and to discontinue product at any time.
Copyright © 2000
Rev. 1.1, 2006-02-27
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 7
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