Design of Low Voltage Transconductor for Fully Differential Gm-C Filter
Seok-Woo Choi, Sun-Hong Kim, Chang-Hun Yun · The Transactions of The Korean Institute of Electrical Engineers · 2007
A fully differential transconductor using the series composite transistor is proposed. Simulation results show that THD is less than 1.2% for the differential input signal of up to when the input signal frequency is 10MHz. i he proposed transconductor is used to design a third-order elliptic Gm-C lowpass filter with 138kHz cutoff frequency for ADSL Tx filter. The design procedure is based on signal flow graph(SFG) of a doubly-terminated LC ladder filter by means of fully differential transconductors and capacitors. The filter is fabricated and measured with a CMOS process.