U642B

U642B Interval- and Wipe/ Wash Wiper Control IC Description As a convenience feature of the windshield wiper intermittent and wipe/wash operation are implemented in most of the automobiles. The U642B is the low-cost solution for an accurate timing function control. Wipe/wash mode has priority over interval mode. Interval pause and afterwiping time can be set to fixed values by using resistors in a broad time range. Added value can be provided with an individual, continuous adjustment of the interval pause by a potentiometer which may be built into the stalk. For proper operation it is mandatory to feed the signal of the wiper motor‘s park switch into U642B. Features D Interval pause: 4 to 20 s D Afterwiping time: 2 to 20 s D Wiper motor’s park switch D Wipe/wash mode priority D One external capacitor, determines all time sequences D Relay driver with Z-diode D Interference protection according to VDE 0839 or ISO/TR 7637/1 D Load-dump protected Block Diagram VS 8 OUT 7 PARK 6 VRef Park switch comparator WASH 5 VRef Input comparator Load-dump comparator VRef Logic VRef Interval comparator Wipe / wash comparator A B C D E F 1 GND 2 INT 3 Ct 4 Rt 94 8950 Figure 1. Block diagram Rev. A4, 10-Apr-01 1 (7) U642B Ordering Information Extended Type Number U642B U642B–FP Package DIP8 SO8 Remarks Pin Description Pin 1 2 3 4 5 6 7 8 Symbol GND INT Ct Rt WASH PARK OUT VS Ground Interval switch Timing capacitor C2 Afterwiping time resistance Wipe/Wash switch Park switch...