This paper presents a methodology for the design of band-pass Σ Δ modulators. The proposed procedure does not force the modulator central frequency fn to one quarter of the sampling frequency fs (or to one of its odd multiples), nor imposes each resonator to have an order higher than 2, as a 2 -path and an N-path transformation would respectively do. Starting from the synthesis of the noise transfer function (NTF), which can be accomplished using some MATLAB functions, it is possible to derive the transfer functions of the resonators making up the modulator. To validate the proposed methodology, this paper also illustrates the design of a 4th order band-pass Σ Δ modulator having a 400-kHz central frequency, a sampling frequency of 6.4 MHz and OSR equal to 160, used to drive an ultrasonic transducer and achieving a dynamic range of 72.5 dB.
A Generalized Design Methodology for Band-Pass ΣΔ Modulators
Rossini C.
;Moisello E.;Aprile A.;Bonizzoni E.;Malcovati P.
2025-01-01
Abstract
This paper presents a methodology for the design of band-pass Σ Δ modulators. The proposed procedure does not force the modulator central frequency fn to one quarter of the sampling frequency fs (or to one of its odd multiples), nor imposes each resonator to have an order higher than 2, as a 2 -path and an N-path transformation would respectively do. Starting from the synthesis of the noise transfer function (NTF), which can be accomplished using some MATLAB functions, it is possible to derive the transfer functions of the resonators making up the modulator. To validate the proposed methodology, this paper also illustrates the design of a 4th order band-pass Σ Δ modulator having a 400-kHz central frequency, a sampling frequency of 6.4 MHz and OSR equal to 160, used to drive an ultrasonic transducer and achieving a dynamic range of 72.5 dB.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
