I am in the debug phase of my DSP board which is based on TI DM6437. The board is working OK, except the Video-Out and I couldn't debug the problem:
I uses the composite video out directly from the DAC_IOUT_D pin to an OpAmp buffer.
The scope trace of this signal (at the input of the OpAmp) shows very weak video signal (~0.2V) which is riding on ~1.5V DC offset.
The voltages DAC_VREF , VDDA_1P1V and VDDA_1P8V are OK.
The DAC_RBIAS is shorted directly to the ground (no resistor). I realized now that I should have connect this pin through a 4K resistor. Could be any other reasone to the above phenomenon?
Thanks.
