GS6042

Final Data Sheet

Rev. 3

PDS-060055

May 2014

13 of 21

Proprietary and Confidential

www.semtech.com

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.

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.

4.6 GAIN_SEL

The GS6042 provides the option of compensating for 6dB of flat attenuation prior to the

equalizer.

Table 4-2: CD Output

CD

Input Status

0

Valid input on SDI/SDI pins

1

Input is not valid

Table 4-3: SLEEP Input

SLEEP

Function

0

Normal operation

1

Low-power sleep mode; CD output

remains valid

Table 4-4: GAIN_SEL Input Table

GAIN_SEL

Function

0

No flat band gain is applied

1

6dB of flat band gain applied to input

signal