OTA-C Biquad-Based Filter Silicon Compiler

  • Michael R. Kobe
  • Edgar Sánchez-Sinencio
  • Jaime Ramírez-Angulo
Part of the The Springer International Series in Engineering and Computer Science book series (SECS, volume 226)


An integrated software system that facilitates the design, and integrated-circuit layout of continuous-time OTA-C filter biaquad-based structures with typical cutoff frequenceis for a 3µmtechnology in the 500 kHz-8 MHz range is described. The proposed integrated software system consists of three separate software modules written in the C language for the Apollo workstation (DN3000). The first module is a general filter approximation package. This program can approximate conventional magnitude, arbitrary magnitude, arbitrary group delay equalizer, arbitrary magnitude with group delay specifications. The second module aides in the synthesis of the biquad-based OTA-C filter structures. This module is unique in that the C code has the rule-based language CLIPS embedded within the code, and takes into account OTA-C filter nonidealities. An expert system using CLIPS was developed to select an appropriate OTA-C filter structure based on the nonidealities of the structures. After the filter structure has been chosen, the program will guide the user in the calculation of the capacitor values. These calculations are based on the nonidealities of the OTAs included in the standard cell library for layout, in addition the design of special purpose OTA as another alternative is also considered. Furthermore, the program will develop the necessary input files for the layout generator. The final module is a modified version of AIDE2, a standard cell layout generator for switched-capacitor circuits. The input files to the modified AIDE2 is a C language program that describes the circuit (i.e., standard cells and their netlist). The output file is a CALTECH Intermediate Format (CIF) file that is required for fabrication.


Group Delay Standard Cell Filter Structure Excess Phase Window Specification 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer Science+Business Media New York 1993

Authors and Affiliations

  • Michael R. Kobe
    • 1
  • Edgar Sánchez-Sinencio
    • 2
  • Jaime Ramírez-Angulo
    • 3
  1. 1.MotorolaWest, AustinUSA
  2. 2.Department of Electrical EngineeringTexas A&M UniversityCollege StationUSA
  3. 3.Department EE&CENew Mexico State UniversityLas CrucesUSA

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