Analysis of switched-capacitor common-mode feedback circuit

A detailed analysis of the dc behavior of switched-capacitor common-mode feedback circuit (SC-CMFB) is presented. A mathematical model, useful for analysis, is developed and the expressions for the output common-mode (CM) voltage, with and without considering the charge injection of switches and leakage currents, are derived. Further, the expression for dc CM settling time, is presented. The effect of parasitic capacitances, dc CM gain, charge injection error, and leakage currents, on the steady-state value of the dc CM voltage is analyzed and design guidelines to minimize these errors are presented. Finally, an improved version of the SC-CMFB circuit is analyzed. This circuit has very low errors due to charge injection and leakage currents and settles much faster than the traditional SC-CMFB circuit.

[1]  M. M. Green,et al.  An approach to fully differential circuit design without common-mode feedback , 1996 .

[2]  Behzad Razavi,et al.  Principles of Data Conversion System Design , 1994 .

[3]  Kenneth R. Laker,et al.  Design of analog integrated circuits and systems , 1994 .

[4]  Stephen H. Lewis,et al.  Determination of stability using return ratios in balanced fully differential feedback circuits , 1995 .

[5]  Kwang Young Kim,et al.  A 10-b, 100-MS/s CMOS A/D converter , 1997 .

[6]  Yannis Tsividis,et al.  Fully differential operational amplifiers with accurate output balancing , 1988 .

[7]  David A. Johns,et al.  Analog Integrated Circuit Design , 1996 .

[8]  R. Bouchakour,et al.  A comparative study of two SC-CMFB networks used in fully differential OTA , 1998, 1998 IEEE International Conference on Electronics, Circuits and Systems. Surfing the Waves of Science and Technology (Cat. No.98EX196).

[9]  J. F. Duque-Carrillo Control of the common-mode component in CMOS continuous-time fully differential signal processing , 1993 .

[10]  U. Kleine,et al.  A low voltage differential op amp with novel common mode feedback , 1998, 1998 IEEE International Conference on Electronics, Circuits and Systems. Surfing the Waves of Science and Technology (Cat. No.98EX196).

[11]  C.A. Laber,et al.  A family of differential NMOS analog circuits for a PCM codec filter chip , 1982, IEEE Journal of Solid-State Circuits.

[12]  ffalourd,et al.  Integrated Circuit Design , 2016, Lecture Notes in Computer Science.

[13]  R. Castello,et al.  A high-performance micropower switched-capacitor filter , 1985, IEEE Journal of Solid-State Circuits.

[14]  Robert G. Meyer,et al.  Analysis and Design of Analog Integrated Circuits , 1993 .

[15]  Alan B. Grebene,et al.  Analog Integrated Circuit Design , 1978 .