High-accuracy charge-redistribution switched-capacitor video bandpass filter in standard 0.8 µm CMOS

A differential switched-capacitor recursive bandpass filter is presented based on a charge-redistribution technique. The centre frequency is 4.286 MHz with a quality factor of 16. It is specifically intended for high frequency de-emphasis of SECAM TV video signals. The active capacitors are realised using only wiring capacitance. A dual-input telescopic OTA is described, which achieves a high feedback factor, in spite of the presence of large parasitic capacitance. The filter consumes only 4 mW for a 5V supply voltage and is realised in 3/4 mm²in a standard 0.8µm double-metal CMOS process.