TY - JOUR
T1 - A design methodology for power-efficient reconfigurable SC ΔΣ modulators
AU - Porrazzo, S.
AU - Morgado, A.
AU - San Segundo Bello, D.
AU - Van Hoof, C.
AU - Yazicioglu, R.F.
AU - van Roermund, A.H.M.
AU - Cantatore, E.
PY - 2015
Y1 - 2015
N2 - This paper presents a methodology to design reconfigurable switched-capacitor delta-sigma modulators (ΔΣMs) capable of keeping their corresponding power efficiency figures constant and optimal for a set of resolutions and signal bandwidths. This method is especially suitable for low-bandwidth, medium-to-high-resolution specifications, which are common in biomedical application range. The presented methodology is based on an analytic model of all different contributions to the power dissipation of the ΔΣM. In particular, a novel way to predict the static power dissipated by integrators based on class A and class AB operational transconductance amplifier is presented. The power-optimal solution is found in terms of filter order, quantizer resolution, oversampling ratio, and capacitor dimensions for a targeted resolution and bandwidth. As the size of the sampling capacitors is crucial to determine power consumption, three approaches to achieve reconfigurability are compared: sizing the sampling capacitors to achieve the highest resolution and keep them constant, change only the first sampling capacitor according to the targeted resolution, or program all sampling capacitors to the required resolution. The second approach results in the best trade-off between power efficiency and simplicity. A reconfigurable ΔΣM for biomedical applications is designed at transistor level in a 0.18-µm complementary metal–oxide–semiconductor process following the methodology discussed. A comparison between the power estimated by the proposed analytic model and the transistor implementation shows a maximum difference of 17%, validating thus the proposed approach.
AB - This paper presents a methodology to design reconfigurable switched-capacitor delta-sigma modulators (ΔΣMs) capable of keeping their corresponding power efficiency figures constant and optimal for a set of resolutions and signal bandwidths. This method is especially suitable for low-bandwidth, medium-to-high-resolution specifications, which are common in biomedical application range. The presented methodology is based on an analytic model of all different contributions to the power dissipation of the ΔΣM. In particular, a novel way to predict the static power dissipated by integrators based on class A and class AB operational transconductance amplifier is presented. The power-optimal solution is found in terms of filter order, quantizer resolution, oversampling ratio, and capacitor dimensions for a targeted resolution and bandwidth. As the size of the sampling capacitors is crucial to determine power consumption, three approaches to achieve reconfigurability are compared: sizing the sampling capacitors to achieve the highest resolution and keep them constant, change only the first sampling capacitor according to the targeted resolution, or program all sampling capacitors to the required resolution. The second approach results in the best trade-off between power efficiency and simplicity. A reconfigurable ΔΣM for biomedical applications is designed at transistor level in a 0.18-µm complementary metal–oxide–semiconductor process following the methodology discussed. A comparison between the power estimated by the proposed analytic model and the transistor implementation shows a maximum difference of 17%, validating thus the proposed approach.
U2 - 10.1002/cta.1992
DO - 10.1002/cta.1992
M3 - Article
VL - 43
SP - 1024
EP - 1041
JO - International Journal of Circuit Theory and Applications
JF - International Journal of Circuit Theory and Applications
SN - 0098-9886
IS - 8
ER -