IEEE Journal of Solid-State Circuits · 2001 · 51 citations · 8 references
EngineeringElectrical EngineeringAnalog ElectronicsMicroelectronicsVlsi DesignAnalog FiltersAnalog Integrated CircuitsCmos Circuit DesignDifferential AmplifiersMixed-signal Integrated Circuit DesignOperational AmplifiersCmos Analog Circuit DesignCmos Analog Integrated CircuitsCmos Operational AmplifiersLinearityOperational Amplifier DesignOutput SwingSwitched-capacitor CircuitsSwitched-capacitor Filters
A modified switched-opamp technique is proposed to enable switched-capacitor (SC) circuits to operate at 1 V with the opamp fully functional in all phases. A 1-V fully differential two-switchable-output-pair operational amplifier has been designed for the proposed technique, which is then employed in a 1-V fully differential SC pseudo-2-path filter. Implemented in a standard single-poly triple-metal 0.5-/spl mu/m CMOS process, the filter achieves a sixth-order bandpass response centered at 75 kHz with a quality factor of 45. Capacitors formed with polysilicon and highly doped n-well (cap-well option) regions are used to achieve both good linearity and small chip area. At 1-V supply, the filter obtains an output swing of 1.2 V/sub pp/ and a dynamic range of 51 db while dissipating 310 /spl mu/W and occupying a chip area of 0.8 mm/sup 2/.
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