GS2993 Datasheet, PDF (15/23 Pages) Gennum Corporation – Automatic power-down on loss of signal

The Carrier Detect output pin (CD) indicates the presence of a valid signal at the input of
the GS2993. When CD is LOW, the device has detected a valid input on SDI and SDI.
When CD is HIGH, the device has not detected a valid input.
The Carrier Detect output still functions when the GS2993 is in sleep mode, such that a
valid Serial Digital Input can be detected at all times. In the sleep state, the carrier detect
functionality requires that the GAIN_SEL input be set to 0.
Auto-Sleep can be enabled by connecting CD to SLEEP. When connected, the GS2993
will automatically go into standby mode when there is a loss of Serial Digital Input
signal.
NOTE 1: CD will only detect loss of carrier for data rates greater than 19Mb/s.
NOTE 2: If the maximum cable length is exceeded (set by the SQ_ADJ pin) and the device
is not in Bypass mode, the CD pin will not be driven LOW, even if a carrier is present.
NOTE 3: If the CD is connected to SLEEP, SQ_ADJ should either be left open, or
connected to ground.
Table 4-2: Sleep Input Table
Sleep
0
1
Function
The GS2993 operates normally
The GS2993 enters sleep mode. CD
output remains valid
Table 4-3: CD Output Table
CD
Input Status
0
Valid Input on SDI, SDI pins
1
Input is not valid
GS2993 Dual Output Adaptive Cable Equalizer
Data Sheet
53966 - 4
August 2012
15 of 23
Propietary & Confidential