Global Mixed-mode Technology Inc.
G218A
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 stan-
dards.
Supports active negation
Current limit and thermal protection
Hot-Swap compatible (Single-Ended)
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 G218A Multi-mode LVD/SE SCSI terminator pro-
vides a smooth transition into the next generation of
the SCSI Parallel Interface (SPI-2). 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 G218A 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 G218A 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-2) bus architectures.
For the SE termination, one regulator and nine preci-
sion 110ohm resistors are used. For the LVD termina-
tion, the G218A integrates two regulated supplies with
nine precision resistor strings.
Applications
Server and workstation
High-end PC
Industrial PC
Disk Array (RAID)
SCSI cable
Pin Configuration
(Top View)
G218A
G218A
VREF
R1+
R1-
R2+
R2-
NC
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
R7-
R7+
R6-
R6+
DIFFB
DIFFSENSE
M/S
VREF
NC
NC
R1+
R1-
R2+
R2-
HS/GND
1
2
3
4
5
6
7
8
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 9
HS/GND 10
R3+
R3-
R4+
R4-
R5+
R5-
DISCNCT
11
12
13
14
15
16
17
GND 18
28Pin SSOP/TSSOP
Ver 3.3
Sep 11, 2001
36Pin SSOP
TEL: 886-3-5788833
http://www.gmt.com.tw
1
GMT [ GLOBAL MIXED-MODE TECHNOLOGY INC ]
