A 10 Gbps differential low-power loss of signal detector for AC-coupled serial transceivers in 28 nm CMOS technology

Abstract

This work presents a differential low-power 10Gbps loss of signal (LOS) detector for high-speed AC-coupled serial transceivers. The detector is designed in 28nm CMOS technology. It includes a novel comparator circuit that compares a differential input signal to a differential reference voltage with minimal sensitivity to the common mode voltage of the input signal. The LOS detector is capable of properly detecting a valid signal that has an external eye opening as low as 85mV and an internal eye opening as low as 36mV at the input pads. It asserts LOS if the external eye opening is below 50mV. It consumes 113uW from a 0.9V nominal power supply at 10Gbps date rate and properly asserts an LOS state in 25.5nS at typical corner operation. It occupies 0.00169mm2 of area. In simulations that include metal parasitic resistance and capacitance, the detector is shown to withstand process, voltage and temperature (PVT) variations and satisfy the commercial operating temperature range. The design and layout of the system were implemented in Synopsys Custom Designer using 28nm CMOS device models.