8fJ/Step Bandpass ADC with Digitally Assisted NTF Re-Configuration

Sanjeev Tannirkulam Chandrasekaran, Gaurav Kapoor, Arindam Sanyal

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


In this work we propose a single channel band-pass (BP) SAR ADC with dynamic noise transfer function (NTF) re-configuration. The proposed ADC employs a low-power two-stage architecture. After the SAR finishes quantization, the residue is extracted by firing the comparator multiple times. An estimate of the residue is obtained by employing a maximum likelihood based estimator (MLE). The output of the ADC is obtained by subtracting a delayed version of the estimated residue from the SAR output thus generating a complex NTF with multiple notches in the spectrum. A 65nm ADC prototype achieves 74.1/78dB SNDR/DR over a 101.2kHz bandwidth while consuming $17~\mu \text{W}$ from a 1V supply at 2.43MS/s. The ADC core occupies an area of 0.12mm2. The ADC achieves 8fJ/c-step bandpass FoM which is $85\times $ better than state-of-the-art BP ADCs with similar bandwidth and $8.7\times $ better than all reported state-of-the-art BP ADCs.

Original languageEnglish (US)
Article number9076001
Pages (from-to)3262-3272
Number of pages11
JournalIEEE Transactions on Circuits and Systems I: Regular Papers
Issue number10
StatePublished - Oct 2020
Externally publishedYes


  • Complex NTF
  • NTF re-configuration
  • SAR
  • band-pass analog-to-digital converter

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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