PIN DESCRIPTIONS
NUMBER
SYMBOL
LEVEL
TYPE
DESCRIPTION
No Connect. Leave these pins floating.
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
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
CD
Analog
Digital
Output
Output
Status Control Signal. The Cable Length Indication (CLI) signal
provides approximate voltage representation of the amount of cable
being equalized.
12
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
EQO_VEE
EQO_VCC
DDO, DDO
Power
Power
Input
Input
Negative Supply. Most negative power supply connection for Equalizer
output buffer stage.
16
Positive Supply. Most positive power supply connection for Equalizer
output buffer stage.
17, 18
ECL/PECL
compatible
Output
Digital Data Output. Differential serial outputs. 50Ω 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 50Ω is maintained between the GS1508 and the
GS1545. 50Ω end termination is recommended.
19
20
DDO_VEE
DDO_EN
Power
Power
Input
Input
Negative Supply. Most negative power supply connection for serial
data output stage.
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
DDO_VCC
SP_VCC
Power
Power
Input
Input
Positive Supply. Most positive power supply connection for serial data
output stage.
30, 31
Positive Supply. Most positive power supply connection for serial to
parallel converter stage.
7 of 19
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