A Continuous-Time Common-Mode Feedback Circuit (CMFB) for High-Impedance Current Mode Application
نویسندگان
چکیده
A continuous-time common-mode feedback circuit (CMFB) is presented. A two-stage high-gain architecture is used to minimize the offset of the common-mode voltage. A special compensation scheme enables this circuit to be used in high-impedance current-mode systems without a stability problem. Simulation and testing results show the superior performance of this circuit. It is proven to be an ideal common-mode feedback circuit for systems which require an accurate and stable commonmode voltage. This circuit has been implemented in a continuous-time switched-current modulator with a 2 m CMOS process. With a 50MHz clock, the modulator has achieved a 60dB dynamic range in a 1MHz bandwidth.
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