Patent ID: 11616576

Abstract:
Transmit-side equalization is disclosed for network devices and network communications methods employing onboard/co-packaged optics. An illustrative network device includes a substrate having a host device IC (integrated circuit) and an optical module IC connected by a short-reach link. The optical module IC having a transmit chain includes a CTLE (continuous time linear equalizer) to at least partly compensate for a channel response of the short-reach link, and a driver that amplifies an output of the CTLE for a photoemitter that couples to an optical fiber. The host device IC includes: a parallel-to-serial converter that produces a digital symbol stream; a digital to analog converter that supplies an analog signal to the short-reach link; and a pre-equalizer coupling the parallel-to-serial converter to the digital-to-analog converter, the pre-equalizer filtering the digital symbol stream to at least partly compensate for a channel response of a combined channel that includes the short-reach link, the CTLE, the driver, and the photoemitter.