Methods and apparatuses for performing common mode pulse compensation in an opto-isolator

摘要

In an opto-isolator, a common mode pulse compensation circuit is provided that senses when a common mode pulse event occurs and that adds current to the LED drive current to compensate for a decrease in the LED drive current caused by the occurrence of the event. The common mode pulse compensation circuit is capable of operating effectively over a very wide range of common mode pulse slopes by automatically adjusting the amount of current that is added to the LED drive current based at least in part on the slope of the sensed common mode pulse. In addition, the common mode pulse compensation circuit is capable of being implemented with LEDs that operate at very low drive currents, which allows the power consumption requirements of the opto-isolator to be reduced.