Linearising Sigma-Delta Modulators Using Dither and Chaos

- Recent work has shown that high-order single-bit sigma-delta modulators suffer from lowlevel artifacts such as idle tones and noise modulation. Techniques that have been proposed to reduce or eliminate these errors include the application of dither inside the one-bit quantiser loop, and selecting a loop filter which makes the modulator chaotic. This paper compares the efficacy of these two approaches by simulating high-resolution sigma-delta modulators suitable for audio-conversion applications. Dynamic-range penalties for successful linearisation are determined for two types of dither signal and two classes of chaos.

• Type: Conference
• Year: 1995
• Where: ISCAS
• Authors: Chris Dunn, Mark B. Sandler
• Keywords: Hardware, ISCAS 1995, One-bit Quantiser Loop, Sigma-delta Modulators, Single-bit Sigma-delta Modulators