Low-power duty-cycle tuned filters

Duty-cycle tuned switched-resistor-MOSFET-C filters can achieve excellent linearity and wide tuning range. In this letter, a switched-capacitor circuit is described which can provide the required bias voltage for the opamp, and relax the driving requirement of the previous block. Correlated double sampling circuit is also realized by the switched-capacitor circuit, to effectively suppress the offset voltage and flicker noise of the amplifier. Simulation results verify that 68dB DC offset voltage suppression could be achieved.