An Asynchronous Delta-Modulator Based A/D Converter for an Electronic System Prototyping Platform

• Published in: IEEE transactions on circuits and systems. I, Regular papers Vol. 63; no. 6; pp. 751 - 762
• Main Authors: Hussain, Wasim, Fakhoury, Hussein, Desgreys, Patricia, Blaquiere, Yves, Savaria, Yvon
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: A/D and D/A conversion; Analog-digital conversion; asynchronous Delta-modulator; Bandwidth; Circuits; Consumption; Conversion; Converters; Data converters; Digital-analog conversion; Electronics; Engineering Sciences; Field programmable gate arrays; Frequency modulation; Low pass filters; Networks; programmable silicon interposer; Spectrum allocation; Variable speed drives
• ISSN: 1549-8328; 1558-0806
• DOI: 10.1109/TCSI.2016.2538019

This paper presents and validates a compact circuitimplementation of an asynchronous Δ-modulator (ADM) for A/D conversion. This data converter was proposed as a means to propagate analog signals into digital interconnection networks. A detailed analysis of the A/D conversion mechanism of the proposed ADM circuit is presented. An analytical method is used to analyze and evaluate the inherent oscillation frequency of the proposed ADM circuit in terms of its circuit parameters. Due to the equivalence of the spectrum of the modulating input signal and the low-frequency spectrum of the ADM output, a simple low-pass filter can be used as a D/A converter to reconstruct the input analog signal. The proposed ADM was fabricated in a 0.13 μm CMOS technology. Measurement results showed SNR and SNDR of 57 and 47 dB respectively for an input bandwidth of 2 MHz. The ADM occupies 45 μm × 22 μm active area. The entire A/D and D/A converter-pair consumes 0.15 mA from a 3.3 V supply and occupies 45 μm × 46 μm area. Compared to other similar A/D converters, the proposed ADM supports moderate signal bandwidth and medium-resolution, while occupying very small area.