Protective circuit for BiCMOS/CMOS circuitry in hybrid VCC systems during H operation

摘要

The present invention relates to a protective circuit for BiCMOS/CMOS circuitry in hybrid VCC systems during H operation. The object of the invention is to create such a protective circuit, which has the least possible influence on the circuitry employing it and only takes up a small amount of space. In order to attain such aim a protective circuit monitors the voltage (VOH) present at its output (AUS) by comparison with a predetermined voltage (REF) and when such predetermined voltage is exceeded it terminates H operation. The protective circuit is so designed that it only taps a negligible monitoring current component (Iex') from the output (AUS).