CMOS-based pseudo ECL output buffer

摘要

The present invention provides a CMOS output buffer with ECL output characteristics that allows the outputs to be terminated in any manner desired and which is not limited by the op amp settling time. The buffer establishes a bus internally for the VOH and VOL levels and then switches between the buses using transmission gates. In the disclosed embodiment of the invention, the op amp's feedback path includes a P-channel device which is either identical to or, to conserve power, a carefully scaled down equivalent of the P-channel output device.