Question about the Continuous-Time Sigma-Delta AD

[gaom9]

Hi,
I read some peper about Continuous-Time Sigma-Delta AD.
But I do not know what is the advantage of it compared to the conventional discontinuous Sigma-Delta AD.
Can anyone tell me something about it, please?



Thank you.
Best regards.

 

[rfsystem]

Anyway the Modulator is Time-Discrete!

The difference is the filter implementation. If you compare both the have because of noise reasons similar cap sizes.

But the switch cap version have to be built with opamps charging the caps in a fraction of the clock cycle. In the continous time filter ony the maximum cap voltage change have to be charged.

That is the reason why they are about 10x and more power efficient.

 

[gaom9]

Hi, rfsystem
What is the advantage of it?
I found it is used in some high speed application, such as wireless receiver.

Thank you.
Best regards!

 

[finfoun]

the continous time modulator's integrator need not swing too much in one clock cycle, so the opamp's slew rate requirement is not as high as discrete one, for this reason the power consumption decreased.