A 40 mV-Differential-Channel-Swing Transceiver Using a RX Current-Integrating TIA and a TX Pre-Emphasis Equalizer With a CML Driver at 9 Gb/s

Abstract

A differential transceiver achieves a 40 mVppd channel signal-swing, a 9 mVppd receiver (RX) input sensitivity, and a 0.59 pJ/b energy efficiency at 9 Gb/s with a 12" FR-4 channel. A current-integrating TIA (CI-TIA) is proposed as a RX pre-amplifier to enhance the RX input sensitivity by increasing the voltage gain of the CI-TIA to around 18 at 9 Gb/s. The RX circuit alone works up to 11 Gb/s with a 1" FR-4 channel. A voltage-mode pre-emphasis equalizer is combined with a current-mode logic (CML) driver at transmitter (TX) to save the low-frequency de-emphasis current of the conventional current-mode equalizer combined with a CML driver. The voltage-mode equalizer consists of a series connection of an inverter and a capacitor; the equalization coefficient is proportional to the supply voltage of the inverter. The transceiver chip in a 65 nm CMOS process consumes 2.8 mW at TX and 2.5 mW at RX with a 1 V supply and a 12" FR-4 channel at 9 Gb/s.