G218A Datasheet, PDF (5/9 Pages) Global Mixed-mode Technology Inc – Multi-mode LVD/SE SCSI Terminator

Global Mixed-mode Technology Inc.
Pin Description (for 28pin SSOP)
G218A
PIN
SYMBOL
DESCRIPTION
1
VREF* Reference Voltage. 2.85-volt reference; a regulator bypass, must be connected to a 4.7µF capacitor.
2-5,7-12,
18-21, 23-26
Rx+, Rx-
Signal Termination. (X=1,2,3,…..9)
Rx+: Ground line for single-ended or positive line for differential applications for the SCSI bus.
Rx-: Signal line/active line for single-ended or negative line in differential applications for the SCSI
bus.
6,22
NC
No Connect. Do not connect these pins.
13
DISCNCT Disconnect. When pulled high, the G218 isolates its bus pins (Rx+, Rx-) from the SCSI bus.
14
GND Ground. Terminator ground pin. Connected to ground.
15
M/S
Master/slave. Used to select which terminator is the controlling device. M/S pin high enables the
DIFFSENSE driver.
16
DIFFSENSE Output to drive the SCSI bus DIFFSENS line.
DIFFB pin should be connected to a 0.1µF capacitor to GND and 20k resistor to SCSI/Bus
17
DIFFB DIFFSENS line. An input pin to detect the type of device (differential or single-ended) on the SCSI
bus.
27,28
TPWR Terminator Power. Connect to the SCSI TERMPWR line and de-couple with a 2.2µF capacitor.
*The VREF keeps the level at 2.85 volt, despite the DISCNCT pin is asserted or not; even the termination mode is changed.
(36pin SSOP)
PIN
SYMBOL
DESCRIPTION
1
VREF* ^{Reference Voltage. 2.85-volt reference; a regulator bypass, must be connected to a 4.7µF capaci-}
tor.
2,3
NC
No Connect. Do not connect these pins.
4-7,11-16,
22-25,
29-32
Signal Termination. (X=1,2,3,…..9)
Rx+
Rx+: Ground line for single-ended or positive line for differential applications for the SCSI bus.
Rx-
Rx-: Signal line/active line for single-ended or negative line in differential applications for the SCSI bus.
8, 9,10,26,
27,28
Heat Sink Ground. Connect to large area PC board traces to increase power dissipation capabil-
HS/GND
ity.
17
DISCNCT Disconnect. When pulled high, the G218 isolates its bus pins (Rx+, Rx-) from the SCSI bus.
18
GND Ground. Terminator ground pin. Connected to ground.
Master/slave. Mode select for the non controlling terminator.
19
M/S
MSTR enables the DIFFSENSE driver.
20
DIFFSENSE Output to drive the SCSI bus DIFFSENS line.
DIFFB pin should be connected to a 0.1µF capacitor to GND and 20k resistor to SCSI/Bus
21
DIFFB DIFFSENS line. An input pin to detect the type of device (differential or single-ended) on the SCSI
bus.
33
SE
Single ended mode indicator. It is HIGH when terminator is operating in SE mode.
34
LVD Low Voltage Differential mode indicator. It is HIGH when terminator is operating in LVD mode.
High Voltage Differential mode indicator. It is HIGH when terminator is operating in HVD mode
35
HVD
or thermal shutdown.
36
TPWR Terminator Power. Connect to SCSI bus TERMPWR line and decouple with 2.2µF capacitor.
*The VREF keeps the level at 2.85 volt, despite the DISCNCT pin is asserted or not; even the termination mode is changed.
Ver 3.3
Sep 11, 2001
TEL: [phone]
http://www.gmt.com.tw
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