Global Mixed-mode Technology Inc.
G218B
Ultra160 Multi-mode LVD/SE SCSI Terminator
Features
Auto-selectable multi-mode Single-Ended
or LVD Termination
Meets SCSI-1, SCSI-2, SCSI-3 SPI Ultra
(Fast-20), Ultra 2(SPI-2 LVD), Ultra160 (SPI-3
LVD) standards.
Supports active negation
3pF channel capacitance
Thermal protection
Hot-Swap compatible
5% tolerance on SE and LVD termination
resistance
28 and 36 pin SSOP package
28 Pin SSOP: Pin Compatible with DS2119
36 Pin SSOP: Pin Compatible with DS2118,
LX5241 and UCC5630
General Description
The G218B Multi-mode LVD/SE SCSI terminator pro-
vides a smooth transition into the next generation of
the SCSI Parallel Interface (SPI-3). It automatically
senses the bus, via DIFFSENS, and switches the ter-
mination to either single-ended (SE) or low voltage
differential (LVD) SCSI, dependent on which type of
devices are connected to the bus. If the G218B de-
tects a HVD SCSI device, it switches to a high imped-
ance state. For a 16-bit Wide SCSI bus to be opera-
tional, three G218B terminators are needed.
The Multi-mode terminator contains all functions re-
quired to terminate and auto detect and switch modes
for SCSI Parallel Interface (SPI) bus architectures. For
the SE termination, one regulator and nine precision
110ohm resistors are used. For the LVD termination,
the G218B integrates 18 regulated supplies with nine
precision resistor strings.
Applications
Server and workstation
High-end PC
Industrial PC
Disk Array (RAID)
SCSI cable
Pin Configuration
G218B
G218B
VREF
R1+
R1-
R2+
R2-
NC/HS GND
R3+
R3-
R4+
R4-
R5+
R5-
DISCNCT
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
TPWR
TPWR
R9-
R9+
R8-
R8+
NC/HS GND
R7-
R7+
R6-
R6+
DIFFB
DIFFSENSE
M/S
VREF
NC
NC
R1+
R1-
R2+
R2-
HS/GND
HS/GND
1
2
3
4
5
6
7
8
9
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
TPWR
HVD
LVD
SE
R9-
R9+
R8-
R8+
HS/GND
HS/GND
HS/GND
R7-
R7+
R6-
R6+
DIFFB
DIFFSENSE
M/S
HS/GND 10
R3+ 11
R3-
R4+
R4-
R5+
R5-
DISCNCT
12
13
14
15
16
17
SSOP-28/TSSOP-28
GND 18
SSOP-36
Ver 1.4
Apr 07, 2005
TEL: 886-3-5788833
http://www.gmt.com.tw
1
GMT [ GLOBAL MIXED-MODE TECHNOLOGY INC ]
