U643B Overview
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. Block Diagram Figure 2-1.
U643B Key Features
- Temperature and Supply Voltage pensated 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 Susceptibility to EMI
- Protection According to ISO/TR 7637/1 Level 4
