What should be the sigma delta output of 1 bit modulator for DC voltage?

Status
Not open for further replies.
N

naisare

Member level 2
Joined
Oct 18, 2004
Messages
43
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,288
Activity points
391
Hi all,
I am designing a sigma delta modulator.

What should be the output of 1 bit modulator for a dc voltage.

For example, if the supply voltage is 1.8V, and if I give input voltage for the modulator as 1.8V dc( or 0.9V or 0.45v), what i should expect as the digital output at the output of the 1-bit modulator.

Does anybody know the equation..

Thanks..
 

Re: sigma delta output

the digital output of a sd mod with dc inut will be alternate 1's and 0's whose avg tend to be the dc input voltage. you can better understand this if u can run an fft on the output of the sd modulator with a dc input. the fft shud have the signal component at dc (0 hz), practically there will be periodic repitition( harmonics) of the dc input( small values) which is limit cycle oscillation and is generally avoided using dithering and other techniques. but for a simulink model with no non idealities, it is going to be a dc component in the fft.
 

Re: sigma delta output

The output will be periodic(may not be alternate 1's and 0's ). this is known as pattern noise.
 

Re: sigma delta output

if the input dc is exactly at the middle of the V+ ref and V- ref then the output will be alternating 1's and 0's.
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…