An Improved linearity ring oscillator-based current-to-digital converter
Many biosensors produce single-ended current outputs. Lab-on-chip applications demand parallel readout channels requiring low area current-to-digital converters. High HD2 has limited the current controlled ring oscillator’s (CCROs) adoption as a low area, single-ended converter. This work improves CCRO open loop linearity by 10 dB. A wide-bandwidth current buffer is also designed. A low area (0.0025 mm 2 ), low power ( 357 μW ), single-ended, and 1 MHz bandwidth converter suitable for array readout is presented with the measured performance.
ADC , Current , Current to digital , Data converters , Direct digitization , Flipped voltage follower (FVF) , Linearization techniques , Phase to digital , Ring oscillator , VCO-based ADC , Inverters , Linearity , Delays , Discharges (electric) , Solid state circuits , Impedance , Biosensors
Wall, A., Walsh, P., Sadeghipour, K., O'Connell, I. and Hare D. (2022) 'An Improved Linearity Ring Oscillator-Based Current-to-Digital Converter', IEEE Solid-State Circuits Letters, 5, pp. 202-205. doi: 10.1109/LSSC.2022.3198367
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