MSc Sehgal

PhD student
Electronic Instrumentation (EI), Department of Microelectronics

PhD thesis (Jul 2021): Calibration Techniques for Power-efficient Residue Amplifiers in Pipelined ADCs
Promotor: Kofi Makinwa

Publications

  1. A Resistive Degeneration Technique for Linearizing Open-Loop Amplifiers
    M. S. Akter; R. Sehgal; K. Bult;
    IEEE Transactions on Circuits and Systems II: Express Briefs,
    Volume 67, Issue 11, pp. 2322-2326, 2020. DOI: 10.1109/TCSII.2020.2966276

  2. Low-Power Analog Techniques, Sensors for Mobile Devices, and Energy Efficient Amplifiers
    K. Bult; M. S. Akter; R. Sehgal;
    Springer, Chapter High-efficiency, , pp. 253-296, 2019.

  3. A 66 dB SNDR Pipelined Split-ADC in 40 nm CMOS Using a Class-AB Residue Amplifier
    M. S. Akter; R. Sehgal; F. van der Goes; K. A. A. Makinwa; K. Bult;
    IEEE Journal of Solid-State Circuits,
    Volume 53, pp. 2939-2950, 10 2018. DOI: 10.1109/JSSC.2018.2859415
    Abstract: ... This paper presents a closed-loop class-AB residue amplifier for pipelined analog-to-digital converters (ADCs). It consists of a push–pull structure with a “split-capacitor” biasing circuit that enhances its power efficiency. The amplifier is inherently quite linear, and so incomplete settling can be used to save power while still maintaining sufficient linearity. This also allows the amplifier’s gain to be corrected by adjusting its bias current. When combined with digital gain-error detection, in this case the split-ADC technique, the result is a power-efficient gain calibration scheme. In a prototype pipelined ADC, this scheme converges in only 12 000 clock cycles. With a near-Nyquist input, the ADC achieves 66-dB SNDR and 77.3-dB SFDR at 53 MS/s. Implemented in 40-nm CMOS, it dissipates 9 mW, of which 0.83 mW is consumed in the residue amplifiers. This represents a 1.8 × improvement in power efficiency compared to state-of-the-art class-AB residue amplifiers.

  4. A 66 dB SNDR Pipelined Split-ADC in 40 nm CMOS Using a Class-AB Residue Amplifier
    M. S. Akter; R. Sehgal; F. van der Goes; K. A. A. Makinwa; K. Bult;
    IEEE Journal of Solid-State Circuits,
    Volume 53, Issue 10, pp. 2939-2950, 10 2018. DOI: 10.1109/JSSC.2018.2859415
    Abstract: ... This paper presents a closed-loop class-AB residue amplifier for pipelined analog-to-digital converters (ADCs). It consists of a push–pull structure with a “split-capacitor” biasing circuit that enhances its power efficiency. The amplifier is inherently quite linear, and so incomplete settling can be used to save power while still maintaining sufficient linearity. This also allows the amplifier’s gain to be corrected by adjusting its bias current. When combined with digital gain-error detection, in this case the split-ADC technique, the result is a power-efficient gain calibration scheme. In a prototype pipelined ADC, this scheme converges in only 12 000 clock cycles. With a near-Nyquist input, the ADC achieves 66-dB SNDR and 77.3-dB SFDR at 53 MS/s. Implemented in 40-nm CMOS, it dissipates 9 mW, of which 0.83 mW is consumed in the residue amplifiers. This represents a 1.8 × improvement in power efficiency compared to state-of-the-art class-AB residue amplifiers.

  5. A 66 dB SNDR pipelined split-ADC using class-AB residue amplifier with analog gain correction
    M. S. Akter; R. Sehgal; F. van der Goes; K. Bult;
    In proc. ESSCIRC,
    pp. 315-318, 2015. DOI: 10.1109/ESSCIRC.2015.7313890

  6. CMOS ultra low-power wavelet filter based sense amplifier for Cardiac signal analysis
    R. Sehgal; A. Singh; W.A. Serdijn;
    In Proc. Workshop on Circuits, Systems and Signal Processing (ProRisc),
    Veldhoven, the Netherlands, pp. 260-266, Nov. 27-28 2008.

BibTeX support

Last updated: 3 May 2022

Rohan Sehgal

Alumnus
  • Left in 2021