DS2125 Datasheet, PDF (1/7 Pages) Maxim Integrated Products – Ultra3 LVD/SE SCSI 15-Line Terminator

DS2125
Ultra3 LVD/SE SCSI 15-Line Terminator
www.maxim-ic.com
GENERAL DESCRIPTION
The DS2125 Ultra3 LVD/SE SCSI terminator is both
a low-voltage differential (LVD) and single-ended
(SE) terminator. The multimode operation enables
the designer to implement LVD in current products
while allowing the end user SE backward
compatibility with legacy devices. If the device is
connected in an LVD-only bus, the DS2125 uses
LVD termination. If any SE devices are connected to
the bus, the DS2125 uses SE termination, which is
accomplished automatically inside the part by
sensing the voltage on the SCSI bus DIFFSENS line.
For the LVD termination, the DS2125 integrates two
current sources with 15 precision resistor strings. For
the SE termination, one regulator and 15 precision
110W resistors are used. Two DS2125 terminators
are needed for a wide SCSI bus.
APPLICATIONS
Raid Systems
SCSI Host Bus Adapter (HBA) Cards
Servers
SCSI Cables
Network Attached Storage (NAS)
Storage Area Networks (SANs)
ORDERING INFORMATION
PART
DS2125
TEMP RANGE
0°C to +70°C
PIN-PACKAGE
48 LQFP
FEATURES
§ Fully Compliant with Ultra3 SCSI
§ Provides Multimode Low-Voltage
Differential/Single-Ended (LVD/SE) Termination
for 15 Signal Line Pairs
§ Auto-Selection of LVD or SE Termination
§ 5% Tolerance on SE and LVD Termination
Resistance
§ Low 3pF Power-Down Capacitance
§ On-Board Thermal-Shutdown Circuitry
§ SCSI Bus Hot-Plug Compatible
§ Fully Supports Actively Negated SE SCSI
Signals
PIN CONFIGURATION
TOP VIEW
HS_GND
HS_GND
HS_GND
VREF
R1P
R1N
R2P
R2N
R3P
R3N
R4P
R4N
R5P
R5N
R6P
R6N
R7P
R7N
R8P
R8N
GND
HS_GND
HS_GND
HS_GND
12 11 10 9 8 7 6 5 4 3 2 1
13
48
14
47
15
Dallas
46
16
Semiconductor
45
DS2125
17
44
18
43
19
42
20
41
21
40
22
39
23
38
24
37
25 26 27 28 29 30 31 32 33 34 35 36
LQFP
HS_GND
HS_GND
HS_GND
TPWR
R15N
R15P
R14N
R14P
R13N
R13P
R12N
R12P
R11N
R11P
R10N
R10P
R9N
R9P
ISO
DIFFSENSE
DIFF_CAP
HS_GND
HS_GND
HS_GND
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata.
1 of 7
REV: 052604