A 70 dB MTPR Integrated Programmable Gain/Bandwidth Fourth-Order Chebyshev High-Pass Filter for ADSL/VDSL Receivers in 65 nm CMOS

This paper presents a fourth-order Chebyshev high-pass filter (HPF) in 65 nm CMOS process with programmable gain and corner frequency to support ADSL and 5/6 band VDSL applications. The HPF improves noise performance by reducing the number of cascaded stages in the receive path and using capacitive feedback to minimize the total number of resistors in the filter. The choice of filter architecture and the optimization of the feedback structure reduce noise for a given total filter capacitance. It achieves a 70 dB MTPR and -161 dBm/Hz (2.8 nV/radicHz ) input-referred noise for ADSL mode. An IM3 of -80 dBc at 10 MHz is measured for VDSL mode. The HPF consumes 236 mW from 2.5 V power supply with active area of 3 mm².