U643B - Flasher IC
The bipolar integrated circuit U643B is used in relay-controlled automotive flashers where a high-level EMC is required.
Lamp outage is indicated by frequency doubling during hazard warning as well as direction mode.
U643B Rev.
4727B *AUTO *09/05 2.
Block Diagram Figure 2-1.
Car Fl
U643B Features
* Temperature and Supply Voltage Compensated Flashing Frequency
* Frequency Doubling Indicates Lamp Outage
* Relay Driver Output with High Current Carrying Capacity and Low Saturation Voltage
* Minimum Lamp Load for Flasher Operation: ≥ 1W
* Very Low Susceptib
