3.1 A 28Gb/s multi-standard serial-link transceiver for backplane applications in 28nm CMOS

Abstract

Broadcom, Irvine, CA Rapid internet traffic growth has fueled the demand for bandwidth in metro networks and data centers and pushed the serial link data rate into 25Gb/s territory, populated by such electrical interface as OIF CEI-25G, CEI-28G [1], IEEE 802.3bj 100G-KR4. To cope with severe channel impairments at 25Gb/s with up to 30dB loss at Nyquist, a feed-forward equalizer (FFE)/decision feedback equalizer (DFE) based transceiver without power-hungry analog-todigital converter (ADC) provides robust performance. This work presents a low-power and area-efficient transceiver that employs a 14-tap adaptive DFE at the receiver (RX) and a 5-tap FFE at the transmitter (TX) for multi-standard applications up to 28Gb/s in 28nm CMOS.

A Robust LC-π Matching Network for 112 Gb/s PAM4 Receiver in 28 nm CMOS

“…At present, the speed of a high-speed serial interface (SerDes) has developed to 112-224 Gb/s PAM4 [1][2][3][4][5][6], which requires 28-56 GHz analog bandwidth. The parasitic capacitance at input/output ports becomes intolerable for such high-speed signal.…”

Design and Comparative Study of Voltage Regulation-Based 2-Tap Flexible Feed-Forward Equalizer for Voltage-Mode Transmitters

“…In addition, this type of driver has worse energy efficiency than a voltage-mode driver. Implementing the FFE in the voltagemode driver can alleviate these issues [9]- [12]. However, in the voltage-mode driver, the output driver segmentation used to implement the equalization limits the FFE resolution, causes routing congestion, and increases the pre-driver complexity [13].…”

“…However, in the voltage-mode driver, the output driver segmentation used to implement the equalization limits the FFE resolution, causes routing congestion, and increases the pre-driver complexity [13]. Therefore, it is difficult to apply these voltage-mode designs [9]- [12] to applications with various channel environments with a single design. That is, the design methodology or process node should be modified depending on the application.…”