### Abstract

In this paper a low-voltage two-stage Op Amp is presented. The Op Amp features rail-to-rail operation and has an input stage with a constant transconductance (gm) over the entire common-mode input range. The input stage consists of an n-and a p-MOS differential pair connected in parallel. The constant gm is accomplished by regulating the tail-currents with the aid of an MOS translinear (MTL) circuit. The resulting gm is constant within 5%. The common-source output range employs a feedback circuit which also contains an MTL circuit. This feedback circuit ensures class AB operation and prevents the transistors in the output stage from cutting off. The Op Amp will be realized in a semi custom CMOS process with minimum channel lengths of 10μm. Simulations show that the minimum supply voltage is less than 2.5 V. A unity gain bandwidth of 550kHz and a DC voltage gain larger than 80 dB are feasible. The input range exceeds the supply rails, whereas the output range reaches the rails within 130 m V.

Original language | English |
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Title of host publication | Proceedings - IEEE International Symposium on Circuits and Systems |

Place of Publication | New York, NY |

Publisher | IEEE |

Pages | 1314-1317 |

Number of pages | 4 |

ISBN (Print) | 0780312813, 9780780312814 |

Publication status | Published - 1 Jan 1993 |

Event | Proceedings of the 1993 IEEE International Symposium on Circuits and Systems - Sheraton Chicago Hotel & Towers, Chicago, United States Duration: 3 May 1993 → 6 May 1993 |

### Publication series

Name | Proceedings - IEEE International Symposium on Circuits and Systems |
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Volume | 2 |

ISSN (Print) | 0271-4310 |

### Conference

Conference | Proceedings of the 1993 IEEE International Symposium on Circuits and Systems |
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Country | United States |

City | Chicago |

Period | 3/05/93 → 6/05/93 |

### Fingerprint

### Cite this

*Proceedings - IEEE International Symposium on Circuits and Systems*(pp. 1314-1317). (Proceedings - IEEE International Symposium on Circuits and Systems; Vol. 2). New York, NY: IEEE.

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*Proceedings - IEEE International Symposium on Circuits and Systems.*Proceedings - IEEE International Symposium on Circuits and Systems, vol. 2, IEEE, New York, NY, pp. 1314-1317, Proceedings of the 1993 IEEE International Symposium on Circuits and Systems, Chicago, United States, 3/05/93.

**A Low-voltage CMOS op amp with a rail-to-rail constant-gm input stage and a class AB rail-to-rail output stage.** / Botma, J. H.; Wassenaar, R. F.; Wiegerink, R. J.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › Academic › peer-review

TY - GEN

T1 - A Low-voltage CMOS op amp with a rail-to-rail constant-gm input stage and a class AB rail-to-rail output stage.

AU - Botma, J. H.

AU - Wassenaar, R. F.

AU - Wiegerink, R. J.

PY - 1993/1/1

Y1 - 1993/1/1

N2 - In this paper a low-voltage two-stage Op Amp is presented. The Op Amp features rail-to-rail operation and has an input stage with a constant transconductance (gm) over the entire common-mode input range. The input stage consists of an n-and a p-MOS differential pair connected in parallel. The constant gm is accomplished by regulating the tail-currents with the aid of an MOS translinear (MTL) circuit. The resulting gm is constant within 5%. The common-source output range employs a feedback circuit which also contains an MTL circuit. This feedback circuit ensures class AB operation and prevents the transistors in the output stage from cutting off. The Op Amp will be realized in a semi custom CMOS process with minimum channel lengths of 10μm. Simulations show that the minimum supply voltage is less than 2.5 V. A unity gain bandwidth of 550kHz and a DC voltage gain larger than 80 dB are feasible. The input range exceeds the supply rails, whereas the output range reaches the rails within 130 m V.

AB - In this paper a low-voltage two-stage Op Amp is presented. The Op Amp features rail-to-rail operation and has an input stage with a constant transconductance (gm) over the entire common-mode input range. The input stage consists of an n-and a p-MOS differential pair connected in parallel. The constant gm is accomplished by regulating the tail-currents with the aid of an MOS translinear (MTL) circuit. The resulting gm is constant within 5%. The common-source output range employs a feedback circuit which also contains an MTL circuit. This feedback circuit ensures class AB operation and prevents the transistors in the output stage from cutting off. The Op Amp will be realized in a semi custom CMOS process with minimum channel lengths of 10μm. Simulations show that the minimum supply voltage is less than 2.5 V. A unity gain bandwidth of 550kHz and a DC voltage gain larger than 80 dB are feasible. The input range exceeds the supply rails, whereas the output range reaches the rails within 130 m V.

UR - http://www.scopus.com/inward/record.url?scp=0027229110&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:0027229110

SN - 0780312813

SN - 9780780312814

T3 - Proceedings - IEEE International Symposium on Circuits and Systems

SP - 1314

EP - 1317

BT - Proceedings - IEEE International Symposium on Circuits and Systems

PB - IEEE

CY - New York, NY

ER -