1 / 17

3V CMOS Rail to Rail Op-Amp

3V CMOS Rail to Rail Op-Amp. AbdelMoneim, K.M.; Mahmoud, S.A.; Microelectronics, 2007. ICM 2007. Internatonal Conference on 29-31 Dec. 2007 Page(s):373 - 376 Digital Object Identifier 10.1109/ICM.2007.4497732 Student : ming-long chuang Date:10/05/2009 National Changhua University

nadda
Télécharger la présentation

3V CMOS Rail to Rail Op-Amp

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 3V CMOS Rail to Rail Op-Amp AbdelMoneim, K.M.; Mahmoud, S.A.;Microelectronics, 2007. ICM 2007. Internatonal Conference on29-31 Dec. 2007 Page(s):373 - 376 Digital Object Identifier 10.1109/ICM.2007.4497732 Student: ming-long chuang Date:10/05/2009 National Changhua University Department of Graduate Institute of Integrated Circuit Design

  2. Outline • Abstract • INTRODUCTION • RAIL TO RAIL INPUT STAGE WITH CONSTANT • RAIL TO RAIL OUTPUT STAGE • SIMULATION RESULTS • CONCLUSION

  3. Abstract • A new CMOS Op-Amp that having a rail to rail operation is presented. The proposed Op-Amp has a constant gm at the input stage. • A cascode stage that achieves a gain greater than 100dB over almost full range of the common mode input voltage. • A common source configuration that increases the output swing between the rails. • A class AB control circuit is used to provide a stable biasing at the output stage.

  4. INTRODUCTION • OP-AMPS are one of the most essential analog building blocks for analog signal processing . One of its crucial advantages is its use in implementing continuous time filters that are used to convert the discrete manner of switched capacitor filters to analog manner.

  5. INTRODUCTION • One of the main drawbacks of using Op-Amps under low voltage is the degradation of its performance over the input range specially at the input stage where the transconductance “gm” is not constant over the entire common mode input voltage “VCM” resulting in stability problems.

  6. r to r input stage with constantGeneral Architecture • The complete input stage architecture with constant gmT.

  7. r to r input stage with constantGeneral Architecture • The transconductance “gm” of a MOS transistor at saturation is given by:

  8. r to r input stage with constantGeneral Architecture • If gmT is made constant over the entire common mode input voltage, a constant gm could be achieved and this will be done by manipulating the sum of tail currents of the differential pairs to be constant over the entire common mode input voltage.

  9. r to r input stage with constantgm-Equalizer Circuit

  10. r to r input stage with constantgm-Equalizer Circuit • Another advantage of this circuit is it’s independence on mismatches of the n-channel and p-channel transistors and thus gmT is kept constant although n p Kn≠Kp which might be caused during the fabrication process.

  11. RAIL TO RAIL OUTPUT STAGE General Architecture • The purpose of the output stage is to provide as large gain as possible and to obtain an output that swings from rail to rail without distortion at high frequency signals. • The common source configuration acts as a buffer to the cascode stage and compensate for its large output resistance and provide the Op-Amp with low output resistance. • The class AB control circuit is used to avoid distortion.

  12. RAIL TO RAIL OUTPUT STAGE General Architecture • Output stage architecture

  13. RAIL TO RAIL OUTPUT STAGE Class AB Control Circuit • Complete output stage

  14. SIMULATION RESULTS

  15. SIMULATION RESULTS • Complete CMOS Op-Amp

  16. Conclusions • This paper introduced a new CMOS low voltage rail to rail Op-Amp that has constant transconductance at the input stage over full range of common mode input voltage with more that 100dB gain without loss of stability. • The proposed Op-Amp has been confirmed using Pspice simulations.

  17. Thank you for your attention

More Related