Asymmetry control for an output driver

摘要

A circuit for controlling signal levels on a transmission channel includes a comparator having a reference voltage input and a current control voltage input. A voltage divider is coupled to the current control voltage input of the comparator. The voltage divider includes multiple loads to divide voltages associated with a first output driver and a second output driver. The voltage divider also includes multiple switches to activate and deactivate loads in the voltage divider. A current control circuit is coupled to an output of the comparator. The current control circuit controls signal levels on the transmission channel in response to an output signal received from the comparator. Another circuit for controlling signal levels on a transmission channel includes a comparator that has a reference voltage input, a current control voltage input, and an offset control input. The offset control input is used to adjust the voltage offset on the transmission channel. A voltage divider is coupled to the current control voltage input of the comparator. The voltage divider divides voltages associated with a first output driver and a second output driver.