GS6042 Datasheet, PDF (13/21 Pages) Semtech Corporation – 6G UHD-SDI/3G/HD/SD Adaptive Cable Equalizer

4.5 Carrier Detect, Sleep, and Auto-Sleep
The Carrier Detect output pin (CD) indicates the presence of a valid signal at the input
of the GS6042. When CD is LOW, the device has detected a valid input on SDI/SDI. When
CD is HIGH, the device considers the input invalid.
Note 1: CD will only detect loss of signal for data rates greater than 19Mb/s.
Note 2: If SQ_ADJ is being used to limit the maximum gain of the device, and the
maximum cable length is exceeded, the CD pin will be set to HIGH even if an input is
present.
Table 4-2: CD Output
CD Input Status
0
Valid input on SDI/SDI pins
1
Input is not valid
The GS6042 also includes a SLEEP input pin, which can be used to put the device into a
low-power sleep mode. In this mode, the outputs are high impedance and will be pulled
high by the on-chip termination. Set the SLEEP pin HIGH to place the chip in this
low-power state. In this mode, the Carrier Detect output will still function to facilitate the
detection of a valid serial input data signal.
Auto-Sleep is enabled by connecting CD to SLEEP. When connected, the GS6042 will
automatically go into low-power sleep mode when there is a loss of input signal.
Note 3: If the CD pin is connected to the SLEEP pin, SQ_ADJ must be either left open, or
connected to ground.
Table 4-3: SLEEP Input
SLEEP
0
1
Function
Normal operation
Low-power sleep mode; CD output
remains valid
4.6 GAIN_SEL
The GS6042 provides the option of compensating for 6dB of flat attenuation prior to the
equalizer.
Table 4-4: GAIN_SEL Input Table
GAIN_SEL
0
1
Function
No flat band gain is applied
6dB of flat band gain applied to input
signal
GS6042
Final Data Sheet
PDS-060055
Rev. 3
May 2014
www.semtech.com
13 of 21
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