5 of 12

32466 - 0

NOT

RECOMMENDED

FOR

NEW

DESIGNS

PIN NO

SYMBOL

TYPE

DESCRIPTION

18

V

CC3

Power Supply. Most positive power supply connection. (VCO, MUX, standards select).

19

CD

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

V

CC4

Power Supply. Most positive power supply connection. (ECL outputs)

27

V

EE2

Power Supply. Most negative power supply connection. (Phase detector, A/D select, Carrier detect)

28

SS

I

Signal Strength Indicator. Analog output which indicates the amount of AGC action. This output

indirectly indicates the amount of equalization and thus cable length.

GS9005B PIN DESCRIPTIONS cont.

Fig. 3 Pins 1, 5 and 6

+

-

+

-

16µA

VCC

2k

2k

1k

1k

1.6V

380µA

50µA

A / D

DDI

Pin 1

Pin 5

Pin 6

DDI

1.2V

INPUT / OUTPUT CIRCUITS