Some design aspects of a two-stage rail-to-rail CMOS op amp

Sander L.J. Gierkink, Peter J. Holzmann, Remco J. Wiegerink, R.F. Wassenaar

    Research output: Contribution to journalArticleAcademicpeer-review

    1 Citation (Scopus)

    Abstract

    A two-stage low-voltage CMOS op amp with rail-to-rail input and output voltage ranges is presented. The circuit uses complementary differential input pairs to achieve the rail-to-rail common-mode input voltage range. The differential pairs operate in strong inversion, and the constant transconductance is obtained by keeping the sum of the square roots of the tail currents constant. Such an input stage has an offset voltage which depends on the common input voltage level, resulting in a poor common-mode rejection ratio. Therefore, special attention has been given to the reduction of the op amp's systematic offset voltage. Gain-boost amplifiers are connected in a special way to provide not only an increase of the low-frequency open-loop gain, but also to provide a significant reduction of the systematic offset voltage.
    Original languageUndefined
    Article number10.1023/A:1008317623471
    Pages (from-to)143-152
    Number of pages10
    JournalAnalog integrated circuits and signal processing
    Volume21
    Issue number2
    DOIs
    Publication statusPublished - Nov 1999

    Keywords

    • IR-62431
    • EWI-13268

    Cite this

    @article{017a058bdf9040a4896fbb848ece7902,
    title = "Some design aspects of a two-stage rail-to-rail CMOS op amp",
    abstract = "A two-stage low-voltage CMOS op amp with rail-to-rail input and output voltage ranges is presented. The circuit uses complementary differential input pairs to achieve the rail-to-rail common-mode input voltage range. The differential pairs operate in strong inversion, and the constant transconductance is obtained by keeping the sum of the square roots of the tail currents constant. Such an input stage has an offset voltage which depends on the common input voltage level, resulting in a poor common-mode rejection ratio. Therefore, special attention has been given to the reduction of the op amp's systematic offset voltage. Gain-boost amplifiers are connected in a special way to provide not only an increase of the low-frequency open-loop gain, but also to provide a significant reduction of the systematic offset voltage.",
    keywords = "IR-62431, EWI-13268",
    author = "Gierkink, {Sander L.J.} and Holzmann, {Peter J.} and Wiegerink, {Remco J.} and R.F. Wassenaar",
    year = "1999",
    month = "11",
    doi = "10.1023/A:1008317623471",
    language = "Undefined",
    volume = "21",
    pages = "143--152",
    journal = "Analog integrated circuits and signal processing",
    issn = "0925-1030",
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    }

    Some design aspects of a two-stage rail-to-rail CMOS op amp. / Gierkink, Sander L.J.; Holzmann, Peter J.; Wiegerink, Remco J.; Wassenaar, R.F.

    In: Analog integrated circuits and signal processing, Vol. 21, No. 2, 10.1023/A:1008317623471, 11.1999, p. 143-152.

    Research output: Contribution to journalArticleAcademicpeer-review

    TY - JOUR

    T1 - Some design aspects of a two-stage rail-to-rail CMOS op amp

    AU - Gierkink, Sander L.J.

    AU - Holzmann, Peter J.

    AU - Wiegerink, Remco J.

    AU - Wassenaar, R.F.

    PY - 1999/11

    Y1 - 1999/11

    N2 - A two-stage low-voltage CMOS op amp with rail-to-rail input and output voltage ranges is presented. The circuit uses complementary differential input pairs to achieve the rail-to-rail common-mode input voltage range. The differential pairs operate in strong inversion, and the constant transconductance is obtained by keeping the sum of the square roots of the tail currents constant. Such an input stage has an offset voltage which depends on the common input voltage level, resulting in a poor common-mode rejection ratio. Therefore, special attention has been given to the reduction of the op amp's systematic offset voltage. Gain-boost amplifiers are connected in a special way to provide not only an increase of the low-frequency open-loop gain, but also to provide a significant reduction of the systematic offset voltage.

    AB - A two-stage low-voltage CMOS op amp with rail-to-rail input and output voltage ranges is presented. The circuit uses complementary differential input pairs to achieve the rail-to-rail common-mode input voltage range. The differential pairs operate in strong inversion, and the constant transconductance is obtained by keeping the sum of the square roots of the tail currents constant. Such an input stage has an offset voltage which depends on the common input voltage level, resulting in a poor common-mode rejection ratio. Therefore, special attention has been given to the reduction of the op amp's systematic offset voltage. Gain-boost amplifiers are connected in a special way to provide not only an increase of the low-frequency open-loop gain, but also to provide a significant reduction of the systematic offset voltage.

    KW - IR-62431

    KW - EWI-13268

    U2 - 10.1023/A:1008317623471

    DO - 10.1023/A:1008317623471

    M3 - Article

    VL - 21

    SP - 143

    EP - 152

    JO - Analog integrated circuits and signal processing

    JF - Analog integrated circuits and signal processing

    SN - 0925-1030

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    M1 - 10.1023/A:1008317623471

    ER -