U2044B Datasheet | Atmel

Features - Temperature and Supply Voltage pensated 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 .. 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 Figure 1. Block Diagram 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 m V 8 30 m W .. Relay 1 2 15 left 31 R5 1.2 k W R7 1.2 k W 4721A- AUTO- 05/03 Pin Configuration Figure 2. Pinning DIP14/SO14 OSC 1 SIL 2 SIR 3 14 OSC 13 OR2 12 VS SIHW 4 .. 11 OR1 10 GND 9 8 VS LD CR1 6 CR2 7 Pin Description Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Symbol OSC SIL SIR SIHW VS CR1 CR2 LD VS GND OR1 VS OR2 OSC Function Oscillator Start input left Start input right Start input hazard warning VS Control input relay 1 Control input relay 2 Lamp failure detection VS IC ground Output relay 1 VS Output relay 2 Oscillator 4721A- AUTO-...