A 1V CMOS fully-differential switched-opamp bandpass Σ Δ modulator

A 2nd order bandpass ΣΔ modulator operating with a single 1V supply voltage has been realized within a standard (VTHn=0.65V, VTHp=0.7V) 0.5µm CMOS technology. In order to avoid the use of on-chip voltage multiplication, the circuit has been designed using the Switched-opamp technique. The use of proposed fully-differential structures has been exploited to increase dynamic range which is about 45dB in a 20kHz bandwidth.