In a previous post, I discussed the trade-offs in linearity of several continuous-time sigma-delta schemes. In this post, I will describe a method that linearizes the sigma-delta noise-shaping filter (NSF). That is, the scheme presented in this article greatly suppresses the linearity requirements on the noise-shaping filter. This method applies to both discrete-time and continuous-time [...]
Tag Archives: linearity
Unity STF | A sigma-delta linearization method
Posted in Analog Professional Also tagged continuous time, continuous time sigma-delta, sigma delta Leave a comment
Continuous time sigma-delta ADC noise shaping filter circuit architectures
The continuous-time sigma-delta (CTSD) analog-to-digital converter (ADC) is a class of sigma-delta analog-to-digital converters that utilize a continuous-time noise-shaping filter (NSF | H(s)). In this post, I analyze a few noise-shaping filter (NSF) architectures that affect highly linear CTSD ADC’s.
Posted in Analog Professional Also tagged active RC, ADC, continuous time, Gm-C, noise shaping filter, sigma delta 5 Comments
Response to edaboard question “How can I deal with 3rd HD in a 2nd SigmaDelta Modulator”
In response to: How can I deal with 3rd HD in a 2nd SigmaDelta Modulator It’s possible that the OTA is limiting you. Doing a matlab model of the sigma-delta and running it should tell you whether it is a circuit problem or a system-level problem. My hunch is that it’s a system-level problem: the [...]
Definition of IP3
This point, where |A×x| = |c×X3| is the third-order intercept point.