celebrevida
Member level 2
I am studying Sigma Delta modulation. I believe I understand the first order basics for both ADC and DACs.
However in the case of Digital to Analog Converter, I am confused. Since you are generating a digital bitstream pattern from a binary input, why do you need the whole Sigma Delta scheme?
I guess my question is for every digital input pattern, why can't you just just use combinational logic or lookup table to generate the pattern and then just stream it one bit at a time for Sigma Delta DAC?
Also, and this applies to both ADCs and DACs, does the actual bit pattern matter or is it just the number of 0s and 1s that you get in a full frame cycle?
For instance in DAC bitstream output, would thermometer code bitstream work just as well as the bitstream that comes out of sigma delta DAC (which tends to NOT be like a thermometer code, the 1s tend to be more "dispersed"). Wouldn't the spectral content be the same either way?
Thanks for any insight.
However in the case of Digital to Analog Converter, I am confused. Since you are generating a digital bitstream pattern from a binary input, why do you need the whole Sigma Delta scheme?
I guess my question is for every digital input pattern, why can't you just just use combinational logic or lookup table to generate the pattern and then just stream it one bit at a time for Sigma Delta DAC?
Also, and this applies to both ADCs and DACs, does the actual bit pattern matter or is it just the number of 0s and 1s that you get in a full frame cycle?
For instance in DAC bitstream output, would thermometer code bitstream work just as well as the bitstream that comes out of sigma delta DAC (which tends to NOT be like a thermometer code, the 1s tend to be more "dispersed"). Wouldn't the spectral content be the same either way?
Thanks for any insight.