G218B Datasheet, PDF (8/11 Pages) Global Mixed-mode Technology Inc – Ultra160 Multi-mode LVD/SE SCSI Terminator

Global Mixed-mode Technology Inc.
Pin Description (for 28pin SSOP/TSSOP)
G218B
PIN
SYMBOL
DESCRIPTION
1
VREF* Reference Voltage. 2.85-volt reference; 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/ HS GND No Connect/ HS GND. Should be grounded for heat sinking purpose.
13
DISCNCT Disconnect. When pulled high, the G218B isolates its bus pins (Rx+, Rx-) from the SCSI bus.
14
GND Ground. Terminator ground pin. Connected to ground.
Master/slave. Used to select which terminator is the controlling device. M/S pin high enables the
15
M/S
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; must be connected to a 4.7µF capacitor.
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. Used to select which terminator is the controlling device. M/S pin high enables the
19
M/S
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.
35
HVD High Voltage Differential mode indicator. It is HIGH when terminator is operating in HVD mode
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 1.4
Apr 07, 2005
TEL: [phone]
http://www.gmt.com.tw
8