GS9005 & GS9005A PIN DESCRIPTIONS cont.
PIN NO
18
19
SYMBOL
V
CC3
CD
TYPE
DESCRIPTION
Power Supply.
Most positive power supply connection. (VCO, MUX, standards select).
Output
Carrier Detect.
Open collector output which goes HIGH when a signal is present at either the Serial
Data inputs or the Direct Digital inputs. This output is used in conjunction with the GS9000B or GS9000S
in the Automatic Standards Select Mode to disable the 2 bit standard select counter. This pin should
see a low impedance (e.g. 1nF to AC Gnd)
20,21
SS0, SS1 Inputs
Standard Select Inputs.
TTL inputs to the 2:4 multiplexer used to select one of four VCO centre
frequency setting resistors (R
VCO0
- R
VCO3
). When both SS0 and SS1 are LOW, R
VCO0
is selected.
When SS0 is HIGH and SS1 is LOW, R
VCO1
is selected. When SS0 is LOW and SS1 is HIGH, R
VCO2
is selected and when both SS0 and SS1 are HIGH, R
VCO3
is selected. These pins should see a
low impedance (e.g. 1nF to AC Gnd)
22,23
SCO/SCO Outputs
Serial Clock Outputs (inverse and true).
Pseudo-ECL differential outputs of the extracted serial clock.
These outputs require 390
Ω
pull-down resistors to V
EE
.
24,25
SDO/SDO Outputs
Serial Data Outputs (inverse and true).
Pseudo-ECL differential outputs of the regenerated serial data.
These outputs require 390
Ω
pull-down resistors to V
EE
.
26
27
28
V
CC4
V
EE2
SSI
Power Supply.
Most positive power supply connection. (ECL outputs)
Power Supply.
Most negative power supply connection. (Phase detector, A/D select, Carrier detect)
Signal Strength Indicator.
Analog output which indicates the amount of AGC action. This output
indirectly indicates the amount of equalization and thus cable length.
INPUT / OUTPUT CIRCUITS
V
CC
+
-
V
CC
V
CC
16µA
2k
2k
1.2V
VCC
1k
1k
A/D
Pin 1
DDI
Pin 5
DDI
Pin 6
+
1.6V
-
50µA
380µA
Fig. 3 Pins 1, 5 and 6
5
520 - 28 - 11
GENNUM [ GENNUM CORPORATION ]
