A continuous-time adaptive FIR equalizer with LNV-AIL delay line for 2.5Gb/s data communication

This paper presents a continuous-time adaptive FIR filter as a fractionally spaced receiver equalizer. Inverter-based delay units with active-inductor load (INV-AIL) are proposed to implement the tap delay line for the bandwidth enhancement. A pulse extraction technique is employed for the equalizer adaptation to different channel characteristics. Implemented in a standard CMOS 0.25-mum process, the proposed adaptive equalizer has achieved over 75% horizontal eye opening when the PCB trace varies from 20 to 120 inches for 2.5Gb/s transmission in the adaptation mode