A continuous-time 7th-order Butterworth Gm-C low pass filter （LPF） with on-chip automatic tuning circuit has been implemented for a direct conversion DBS tuner in 0.35 μm SiGe BiCMOS technology. The filter＇s -3 dB...A continuous-time 7th-order Butterworth Gm-C low pass filter （LPF） with on-chip automatic tuning circuit has been implemented for a direct conversion DBS tuner in 0.35 μm SiGe BiCMOS technology. The filter＇s -3 dB cutoff frequency f0 can be tuned from 4 to 40 MHz. A novel on-chip automatic tuning scheme has been successfully realized to tune and Iock the filter＇s cutoff frequency. Measurement results show that the filter has -0.5 dB passband gain, ＋/- 5% bandwidth accuracy, 30 nV/Hz1/2 input referred noise, -3 dBVrms passband IIP3, and 27 dBVrms stopband IIP3. The I/Q LPFs with the tuning circuit draw 13 mA （with f0 = 20 MHz） from 5 V supply, and occupy 0.5 mm^2.展开更多
文摘A continuous-time 7th-order Butterworth Gm-C low pass filter （LPF） with on-chip automatic tuning circuit has been implemented for a direct conversion DBS tuner in 0.35 μm SiGe BiCMOS technology. The filter＇s -3 dB cutoff frequency f0 can be tuned from 4 to 40 MHz. A novel on-chip automatic tuning scheme has been successfully realized to tune and Iock the filter＇s cutoff frequency. Measurement results show that the filter has -0.5 dB passband gain, ＋/- 5% bandwidth accuracy, 30 nV/Hz1/2 input referred noise, -3 dBVrms passband IIP3, and 27 dBVrms stopband IIP3. The I/Q LPFs with the tuning circuit draw 13 mA （with f0 = 20 MHz） from 5 V supply, and occupy 0.5 mm^2.
