“Supply-less” HDMI source terminated output stage with tuned wide-range programmable termination

摘要

A “supply-less” transmitter output stage is provided for a transmitter. This transmitter output stage can include a tunable source termination and a reference voltage generator. The tunable source termination can be coupled between a differential pair of the transmitter. The reference voltage generator can advantageously generate reference voltages from a far-end termination. These reference voltages provide a way of translating the internal supply voltage level to the pad voltage level to enable/disable the tunable source termination. Also, it provides a way to minimize leakage and minimize the junction stress of switching transistors in the tunable source termination as well as the transmitter. The dependency between the reference voltages and the far-end termination voltage makes this design more portable to other supply voltages and other technologies specifications other than HDMI.