Title :
A 4-40MHz Continuous-Time LPF with on Chip Automatic Tuning for a Direct Conversion DBS Tuner
Author :
Chen, Bei ; Chen, Fangxiong ; Ma, Heping ; Shi, Yin ; Dai, Fa Foster
Author_Institution :
Inst. of Semicond., Chinese Acad. of Sci., Beijing
Abstract :
A continuous-time 8th-order Butterworth Gm-C low pass filter (LPF) has been implemented for a direct conversion DBS tuner in a 0.35 um SiGe BiCMOS technology. The filter´s -3 dB cutoff frequency f0 can be programmed from 4MHz to 40MHz in fine discrete steps through a 7-bit DAC. A PLL-based on chip automatic tuning system is used to maintain the precise filtering characteristics against process variation, temperature drift and aging. The filter has OdB passband gain, 24nV / radicHz input referred noise, -3 dBVrms passband IIP3, 27 dBVrms stopband IIP3. The I/Q channel filters with the tuning system draw 21 mA (with f0=20MHz) from 5 V supply, and occupy an area of 0.5 mm2.
Keywords :
BiCMOS integrated circuits; band-pass filters; circuit tuning; direct broadcasting by satellite; low-pass filters; microprocessor chips; system-on-chip; BiCMOS technology; I/Q channel filter; SiGe; continuous-time 8th-order Butterworth Gm-C low pass filter; continuous-time LPF; direct broadcast satellite tuner; direct conversion DBS tuner; frequency 4 MHz to 40 MHz; on chip automatic tuning; passband filter; size 0.35 mum; BiCMOS integrated circuits; Cutoff frequency; Germanium silicon alloys; Low pass filters; Passband; Satellite broadcasting; Silicon germanium; System-on-a-chip; Tuners; Tuning;
Conference_Titel :
Circuits and Systems for Communications, 2008. ICCSC 2008. 4th IEEE International Conference on
Conference_Location :
Shanghai
Print_ISBN :
978-1-4244-1707-0
Electronic_ISBN :
978-1-4244-1708-7
DOI :
10.1109/ICCSC.2008.69
