I am working with the SD3GDAIII, feeding it with a signal from an HD-SDI pattern generator and connecting SDO- to a 75R terminated scope. In HD mode the fault light illuminates unless I place my finger over the SDO1- trace in the vicinity of the 'REV A' silk marking. Why is this?
The fault light appears to work correctly in SD mode (i.e. only illuminates when output or input cable is removed).
Richard
PS I modified the board to include a pull-up resistor on the cable driver /FAULT line as the LMH0307 datasheet describes this output as open drain and there doesn't appear to be a pull-up in the User Guide schematic (Figure 4).