U2044B

Features Temperature and Supply Voltage Compensated Flashing Frequency Frequency Doubling Indicates Lamp Outage Two Relay Driver Outputs with High Current-carrying Capacity and Low Saturation Voltage Minimum Lamp Load for Flasher Operation: ³ 1 W Very Low Susceptibility to EMI Protection According to ISO/TR7637/1 Level 4 Extremly Low Current Consumption < 10 µA (with Switches Open) Reverse Polarity Protection Three Control Inputs: Left, Right and Hazard Warning Dual Output Flasher U2044B www.DataSheet4U.com Description The integrated circuit U2044B is used in relay-controlled automotive flashers. With two output stages, each side of the vehicle is controlled separately. A left and a right direction indicator input with only a small control current makes switch contacts for small loads possible. The separate hazard warning input simplifies the construction of the hazard switch. Lamp outage is indicated by frequency doubling during direction mode. Thanks to extreme low current consumption the U2044B can be directly connected to the battery. Rev. 4721A–AUTO–05/03 1 Figure 1. Block Diagram 30 9 5 RShunt C1 4.7 µF K1 Contact 1 14 R1 82 k W + V Ref1 1 + 7 + + V S-6 V 27.5 V 11 13 GND R2 220 W Hazard warning R4 4.7 k W R6 4.7 k W right 10 3 2 4 R3 4.7 k W R10 1.2 k W + 12 V Ref2 V S /2 6 R9 47 k W R8 47 k W 2 + V S-81 mV 8 30 m W 30 www.DataSheet4U.com 30 Relay 1 2 15 left 31 12700 R5 1.2 k W R7 1.2 k W 2 U2044B 4721A–AUTO–05/03 U2044B Pin Configur...