GENNUM CORPORATION

522 - 28 - 05

7 of 19

PIN DESCRIPTIONS

NUMBER

SYMBOL

LEVEL

TYPE

DESCRIPTION

1, 2, 3, 4, 6, 8,

9, 10, 11, 14,

15, 22, 23, 24,

25, 26, 27, 28,

29, 37, 38, 39,

40, 51, 52, 57,

58, 65, 66, 67,

68, 69, 70, 71,

77, 78, 82, 83,

84, 87, 88, 90,

92, 94, 95, 97,

99, 100, 101,

102, 103, 104,

107, 114, 115,

116, 118, 119,

121, 123, 125,

127, 128

NC

No Connect. Leave these pins floating.

5

MCLADJ

Analog

Input

Control Signal Input. Adjusts the maximum amount of cable for the

equalizer (from 0m to the maximum cable length). Normally the output

is muted (latched to the last state) when the set maximum cable

length is exceeded. To achieve maximum cable length, this pin should

be left open (floating).

7

CLI

Analog

Output

Status Control Signal. The Cable Length Indication (CLI) signal

provides approximate voltage representation of the amount of cable

being equalized.

12

CD

Digital

Output

Status Signal. The Carrier Detect indicator is used as an output status

signal.

When the CD output is low, the carrier is present and the data output

is active.

When the CD output is high, the carrier is not present and the data

output is muted (latched to the last state). This indicates that the

maximum cable length as set by MCLADJ has been reached.

13

Power

Input

Negative Supply. Most negative power supply connection for Equalizer

output buffer stage.

16

Power

Input

Positive Supply. Most positive power supply connection for Equalizer

output buffer stage.

17, 18

DDO, DDO

ECL/PECL

compatible

Output

Digital Data Output. Differential serial outputs. 50

Ω pull up resistors are

included on chip. Note that these outputs are not cable drivers.

Ensure that the trace length between the GS1545 and the GS1508

Cable driver is kept to a minimum and that a PCB trace characteristic

impedance of 50

Ω is maintained between the GS1508 and the

GS1545. 50

Ω end termination is recommended.

19

Power

Input

Negative Supply. Most negative power supply connection for serial

data output stage.

20

DDO_EN

Power

Input

Control Signal Input. Used to enable or disable the serial output stage.

If a loop through function is not required, then this pin should be tied

to the most positive power supply voltage.

When DDO_EN is tied to the most negative power supply voltage, the

DDO, DDO outputs are enabled.

When DDO_EN is tied to the most positive power supply voltage, the

DDO, DDO outputs are disabled.

21

Power

Input

Positive Supply. Most positive power supply connection for serial data

output stage.

30, 31

Power

Input

Positive Supply. Most positive power supply connection for serial to

parallel converter stage.