A CMOS Mixed-Mode Sample-and-Hold Circuit for Pipelined ADCs

  • Shan Jiang
  • Manh Anh Do
  • Kiat Seng Yeo
Conference paper
Part of the IFIP International Federation for Information Processing book series (IFIPAICT, volume 249)

This paper describes the design of a high-speed CMOS sample and- hold (S/H) circuit for pipelined analog-to-digital converters (ADCs). This S/H circuit consists of a switched-capacitor (SC) amplifier and a comparator to generate the mixed-mode sampled output data, which are represented both in analog and digital forms. The mixed-mode sampling technique reduces the operational amplifier (op amp) output swing. As a result, the requirements on op amp DC gain, slew rate and bandwidth are relaxed; the linearity of the SC amplifier is also improved. The reduction of signal swing in the front-end also brings benefit to the pipelined stages in speed and power consumption. The aperture errors at high frequency are minimized by time constant matching and digital error correction logic in the pipelined ADC. Designed in a 0.18-µm CMOS process, the proposed S/H circuit operates up to 200-MSample/s with a total harmonic distortion (THD) less than -60 dB and a signal-to-noise and distortion ratio (SNDR) larger than 59 dB in the worst-case simulation. The power consumption of the mixed-mode S/H circuit is 3.6-mW with 1.8-V supply voltage.


Total Harmonic Distortion Slew Rate Pipeline Stage Gain Error Output Swing 
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  1. 1.
    D.-Y. Chang, “Design Techniques for a Pipelined ADC Without Using a Front-End Sample-and-Hold Amplifier,” IEEE Trans. Circuits and Systems I, vol. 51, pp. 2123-2132, Nov. 2004.CrossRefGoogle Scholar
  2. 2.
    H.-C. Kim, D.-K. Jeong, and W. Kim, “A Partially Switched-Opamp Technique for High-Speed Low-Power Pipelined Analog-to-Digital Converters,” IEEE Trans. Circuits and Systems I, vol. 53, pp. 795-801, Apr. 2006.Google Scholar
  3. 3.
    I. Mehr and L. Singer, “A 55-mV, 10-bit, 40MSample/s Nyquist-Rate CMOS ADC,” IEEE J. Solid-State Circuits, vol. 35, pp. 318-325, Mar. 2000.CrossRefGoogle Scholar
  4. 4.
    B. Razavi,“Design of Analog CMOS Integrated Circuits,” McGraw-Hill Higher Ed-ucation, 2001.Google Scholar
  5. 5.
    C. C. Enz and G. C. Temes, “Circuit Techniques for Reducting the Effects of Op-Amp Imperfections: Autozeroing, Correlated Double Sampling, and Chopper Sta-bilization,” Proceedings of the IEEE, vol. 84, pp. 1584-1614, Nov. 1996.CrossRefGoogle Scholar
  6. 6.
    K. Bult and G. J. G. M. Geelen, “A Fast-Settling CMOS Op Amp for SC Circuits with 90-dB DC Gain,” IEEE J. Solid-State Circuits, vol. 25, pp. 1379-1384, Dec. 1990.CrossRefGoogle Scholar
  7. 7.
    B. Y. Kamath, R. G. Meyer, and P. R. Gray, “Relationship Between Frequency Response and Settling Time of Operational Aplifiers,” IEEE J. Solid-State Circuits, vol. sc-9, pp. 347-352, Dec. 1974.CrossRefGoogle Scholar
  8. 8.
    M. Dessouky, A. Kaiser, “Input Switch Configuration for Rail-to-Rail Operation of Switched Opamp Circuits,” Electronics Letter, vol 35, pp. 8-10, Jan. 1999.CrossRefGoogle Scholar

Copyright information

© International Federation for Information Processin 2008

Authors and Affiliations

  • Shan Jiang
    • 1
  • Manh Anh Do
    • 1
  • Kiat Seng Yeo
    • 1
  1. 1.School of Electrical & Electronic EngineeringNanyang Technologies UniversitySingapore

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