A 25Gb/s serial-link repeater with receiver equalization and transmitter de-emphasis in 0.13μm SiGe BiCMOS

A serial-link repeater chip with a single stage continuous-time linear equalizer (CTLE) and a 3-tap feedforward equalizer (FFE) is realized in a 0.13μm SiGe BiCMOS technology. The CTLE with the negative capacitance circuits is implemented to achieve a larger high-frequency boosting at the receiver side. By utilizing the LC-based delay elements, the FFE accomplishes the transmitter de-emphasis without retiming clocks. The measurement results show that the repeater can at least compensate for a Nyquist channel loss of 23.5dB (14.4dB by the receiver equalization and 9.1dB by the transmitter de-emphasis) when operating at the data rate of 25Gb/s. The total power consumption is 230mW from a 3.3V power supply.