Energy‐efficient high‐accuracy switching method for SAR ADCs

Abstract

A new tri-level switching method for successive approximation register (SAR) analogue-to-digital converters (ADCs) is presented. The proposed switching method enhances the efficiency of digital-to-analogue converter switching energy by 93.7% and achieves a 75% reduction in the total capacitor size, compared with the conventional SAR ADC. In addition, the accuracy of the proposed SAR ADC has no dependency on the accuracy of the mid-level reference voltage (V cm) except in the least significant bit, and the common-mode voltage at the input of the comparator will remain approximately unchanged. Analytical calculations and behavioural simulation results are provided to demonstrate the effectiveness of the proposed switching scheme.

Energy-efficient and reference-free monotonic capacitor switching scheme with fewest switches for SAR ADC

“…Clearly, the common-mode voltage of the capacitor arrays converges to the ground, which is always below the input common-mode voltage. One bit only needs one capacitor switching and the switching operations are all downward, which results in simpler digital control logic and simplifies the design complexity compared to [2,3,4,5].…”

“…Thus, the principal source of energy consumption in the SAR ADC is the DAC switching. During the past few years, some low-power switching methods have been actively introduced for the DAC to consume less energy [1,2,3,4,5]. With the conventional switching method as a reference, the set and down [1], tri-level [2], high-accuracy [3], chargeaverage [4] and Mohsen tri-level [5] reduce the switching energy by 81.2, 96.89, 93.7, 93.5 and 97.26%, respectively.…”

“…During the past few years, some low-power switching methods have been actively introduced for the DAC to consume less energy [1,2,3,4,5]. With the conventional switching method as a reference, the set and down [1], tri-level [2], high-accuracy [3], chargeaverage [4] and Mohsen tri-level [5] reduce the switching energy by 81.2, 96.89, 93.7, 93.5 and 97.26%, respectively. However, the tri-level [2], high-accuracy [3] and Mohsen tri-level [5] ones require the third reference V CM which consumes much power to be generated.…”

“…With the conventional switching method as a reference, the set and down [1], tri-level [2], high-accuracy [3], chargeaverage [4] and Mohsen tri-level [5] reduce the switching energy by 81.2, 96.89, 93.7, 93.5 and 97.26%, respectively. However, the tri-level [2], high-accuracy [3] and Mohsen tri-level [5] ones require the third reference V CM which consumes much power to be generated. The set and down [1] and charge-average [4] ones need only two references but are not energy-efficient because the dummy capacitor in [1] is not fully used and [4] requires the reset energy, more switches and transmission gates.…”

Energy-efficient and area-efficient switching scheme based on multi-reference for SAR ADC

“…By introducing V CM , switching energy and capacitor area in [1,2,3,4,5,6] have been reduced significantly. The tri-level switching scheme [1], the M. Shahmohammadi switching method [2], the highaccuracy switching technique [3], V CM -based monotonic one [4], the hybrid one [5] and multi-reference technique [6] reduce power dissipation by 96.89, 97.27, 93.7, 97.66, 98.83 and 97.7%. However, the comparator input common-mode voltage is not constant except in [1], which decays the comparator resolution.…”