A passive 2nd-order sigma-delta modulator based on a cascade of first-order lowpass filters was designed, fabricated, and tested. A lumped RC filter is added in the loop of a conventional 1st-order passive sigma-delta modulator in order to improve the linearity of its transfer function. A low power edge-triggered comparator was designed and fabricated along with lumped components in ON Semicond...

Sigma-delta ACD has two main parts: analog modulator and digital filter, the performance of modulator determines the performance of sigma-delta ADC, so the design of modulator is very important. The paper introduces the principle of sigma-delta AD modulator with high accuracy and the applied over sampling technique, noise shaping technique and multi-bit quantizer technique. Determining the desi...

This paper describes a new firstand second-order delta-sigma modulator concept where the first integrator is extracted and implemented by a frequency modulator with the modulating signal as the input. The result is a simple delta-sigma modulator with no need for digital-to-analog converters, allowing straight-forward multi-bit quantization. Without the frequency modulator, the circuit becomes a...

Switched capacitor (SC) based modulator is prone to various non-idealities; especially at the circuit designing stage where the integrator plays an important role and effects the overall performance of the sigma delta modulator. The non idealities take account of sampling jitter which includes the effect of switching circuitry, sampling noise. Opamp parameter include noise, finite dc gain, fini...

IEEE Trans. Circuits Syst II, vol. 48, no. 3, pp. 233{244, March 2001 Stability and Performance Analysis of an Adaptive Sigma Delta Modulator Mansour A. Aldajani, Student Member, IEEE, and Ali H. Sayed, Fellow, IEEE Abstract| This work develops an adaptive sigma delta modulator that is based on adapting the quantizer stepsize using estimates of the quantizer input rather than the modulator inpu...

In this paper a reconfigurable switched-current sigma delta modulator for power amplifier is shown, which is a suitable topology to save energy and integrated area in portable applications. Results have shown the correct operation of a 1.8V, 0.18μm CMOS reconfigurable switched-current sigma delta modulator with 11bits dynamic range within 1MHz and 7.8bits within 3.8MHz bandwidth.

This paper deals with a system-level optimization of a back-end of audio signal processing chain for hearing-aids, including a sigma-delta modulator digital-to-analog converter (DAC) and a Class D power amplifier. Compared to other stateof-the-art designs dealing with sigma-delta modulator design for audio applications we take the maximum gain of the modulator noise transfer function (NTF) as a...

We present a globally stable arbitrary-order single-bit delta-sigma modulator architecture with continuous-time loop filtering. Using Lyapunov arguments and the method of equivalent control, it is shown that stability is guaranteed for any input signal with peak magnitude less than L > 0, where L and +L denote the quantization levels. The design augments the conventional deltasigma modulator wi...