A 16-port FCC-compliant 10GBase-T transmitter and hybrid with 76dBc SFDR up to 400MHz scalable to 48 ports

High-density 48-port network switches demand very power-efficient, small form-factor quad PHYs which comply with the IEEE 802.3an transmit PSD and return-loss requirements on the one hand and meet the FCC Class-A specifications on the other hand. We present a 10GBase-T transmitter and hybrid that uses a highly correlated current-mirroring amplifier with output rise time control and high CMRR to perform a first-order linear and non-linear echo cancellation while enabling the design of 48-port FCC compliant network switches. Experimental results over the 400MHz bandwidth exhibit a transmitter linearity of >;57dBc as well as a residual linear echo and distortion of -28dBc and 76dBc, respectively. Implemented in a 40nm CMOS technology, the transmitter plus hybrid consumes 200mW power and occupies 0.5mm².