Analysis of VCO based noise shaping ADCs linearized by PWM modulation

Author

Hernandez, L. ; Prefasi, E. ; Paton, Susana ; Rombouts, P.

Author_Institution

Electron. Technol. Dept., Carlos III Univ. of Madrid, Leganes, Spain

fYear

2012

fDate

9-12 Dec. 2012

Firstpage

352

Lastpage

355

Abstract

Nonlinearity is one of the main problems associated with VCO based noise shaping ADCs. Their open loop architecture does not permit correction of the nonlinear voltage to frequency response of the VCO by feedback. Recently, linearization of a VCO ADC by Pulse Width Modulation (PWM) precoding has been proposed. Here, the input signal is encoded by a PWM modulator to drive the VCO with a 2-level signal, thus eliminating the nonlinearity of the VCO. This paper analyzes the remaining inherent distortion in such modulators which originates from subsampling the PWM sidebands.

Keywords

analogue-digital conversion; frequency response; precoding; pulse width modulation; voltage-controlled oscillators; 2-level signal; PWM modulation precoding; PWM sideband subsampling; VCO nonlinearity; VCO-based noise shaping ADC linearization; frequency response; nonlinear voltage; open loop architecture; pulse width modulation precoding; Amplitude modulation; Frequency modulation; Noise; Noise shaping; Pulse width modulation; Voltage-controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronics, Circuits and Systems (ICECS), 2012 19th IEEE International Conference on

Conference_Location

Seville

Print_ISBN

978-1-4673-1261-5

Electronic_ISBN

978-1-4673-1259-2

Type

conf

DOI

10.1109/ICECS.2012.6463729

Filename

6463729