M02044CG-31 Datasheet, PDF (12/22 Pages) M/A-COM Technology Solutions, Inc. – 3.3/5V Limiting Amplifier for Applications from 100 Mbps to 622 Mbps

Functional Description
Figure 3-4. ST and LOS Output
V_CC
80 kΩ
Either
LOS or
ST
R_ST establishes a threshold voltage at the ST_SET pin as shown in Figure 3-5. Internally, the input signal level is
monitored by the Level Detector which creates a DC voltage proportional to the input signal peak to peak value.
The voltage at ST_SET is internally compared to the signal level from the Level Detector. When the Level Detect
voltage is less than V_(STSET), LOS is asserted and will stay asserted until the input signal level increases by a
predefined amount of hysteresis. When the input level increases by more than this hysteresis above V_(STSET), LOS
is deasserted. See the applications information section for the selection of R_ST.
Note that ST_SET can be left open if the loss of signal detector function is not required. In this case LOS would be
low.
Figure 3-5. STset Input
V_CC3
V_CC
R_ST
ST_SET
V_STSET
3.3.5
JAM Function
When asserted, the active high power down (JAM) pin forces the outputs to a logic “one” state. This ensures that
no data is propagated through the system. The loss of signal detection circuit can be used to automatically force
the data outputs to a high state when the input signal falls below the threshold. The function is normally used to
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