Could I know if the SD Luma Scale Control will take effect on AGC pulse, F/Back porch pulse level?
As per expert comment, SD Luma scale control will effect Lume/Chroma values but Syncs are in fixed voltage levels.
By using SD luma and color scale control, customer can increase the gain between 3.5% and 4.5%. This setting is described on P57 of the datasheet and it provides a way to increase the output level by a scaling factor. Enabling this setting should give the customer the desired behavior.
Also please refer here https://ez.analog.com/video/f/q-a/6192/adv739x-how-to-calculate-the-dac-gain/22052
Note: Lower resistor( lower Rset resistor a bit) --> More DAC output current --> High DAC output voltage