The design of the U6433B is similar to that of U6043B, both devices have the same excellent EMC (Electro Magnetic Capability) and protection features. The U6433B includes an additional 8-mV comparator and a logical connection with the frequency doubling stage. This combination can be used for a hazard switch which bypasses the external shunt resistor to disable the frequency doubling. This feature is especially important with respect to the US automotive industry. During direction mode the U6433B works like other flashers, i.e., frequency doubling in the case of lamp outage.