Selectable low-voltage differential signal/current mode logic (LVDS/CML) receiver with the option of AC or DC coupling

摘要

A selectable receiver includes a first receiver module for receiving first input signal type and a second receiver module, different from the first receiver module, for receiving a second input signal type, both receiver modules coupled to the same receiver inputs. An internal common mode voltage for the first signal type or for the second signal type, is provided by respective common mode voltage networks, to the first or to the second receiver module, to facilitate AC coupling with the appropriate DC common mode voltage required by the signal type. If direct coupled, the internal common mode voltage is effectively swamped out by the common mode voltage of the input signal. The first receiver module or the second receiver module, and the associated first common mode voltage or second common mode voltage, are selected in the receiver based on a control signal. The first receiver module can be a current mode logic (CML) receiver, and the second receiver module can be a low-voltage differential (LVDS) receiver module, e.g., a self-timed interface (STI) receiver module.