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 Interval pause: 4 to 20 s One external capacitor, determines all time sequences Afterwiping time: 2 to 20 s Relay driver with Z-diode Wiper motor’s park switch Interference protection according to VDE 0839 or ISO/TR 7637/1 Wipe/wash mode priority Load-dump protected Block Diagram VS 8 OUT PARK 7 WASH 6 5 VRef VRef Park switch comparator Load-dump comparator Input comparator VRef Logic Wipe / wash comparator VRef Interval comparator 1 GND A B 2 INT C D 3 Ct E F 4 Rt 94 8950 Figure 1. Block diagram Rev. A4, 10-Apr-01 1 (7) U642B Ordering Information Extended Type Number Package U642B DIP8 U642B–FP SO8 Remarks Pin Description Pin Symbol Function 1 GND Ground 2 INT Interval switch 3 Ct Timing capacitor C2 4 Rt Afterwiping time resistance 5 WASH Wipe/Wash switch 6 PARK Park switch for wiper motor 7 OUT Relay control output 8 VS GND 1 8 VS INT 2 7 OUT Ct 3 6 PARK Rt 4 5 WASH U642B 93 7691 Supply voltage KI. 15 Figure 2. Pinning Circuit Description Interval Function, Pin 2 By closing the interval switch, S2, to supply voltage, VBatt, the relay is activated. The internal current source (Pin 3) which holds the capacitor C2 in charged state is switched-off. As soon as there is a positive potential at the park switch (S1), the current source F (see figure 1) charges the capacitor C2 very fast. After the wiper operation is finished, S1 is again at ground potential, the relay is in ”off” position – interval pause begins – the capacitor C2 is discharged through the current source C, till the voltage at Pin 3 is below the threshold of 2 V. Interval pause can be adjusted between 4 s to 20 s with the help of potentiometer R3. Now the relay switches on and the next interval cycle begins. Opening of switch S2 causes the current source A to discharge C2 immediately and current sources C and F are switched-off. Wipe/Wash (WIWA) Operation, Pin 5 By closing the WIWA-switch, S3, to supply voltage, VBatt, the water pump starts spraying water on the windscreen, the current source A is switched-off which keeps the capacitor C2 in discharged state. Now the capacitor is charged through the current sources D and F, and when after a time interval of approximately 100 ms, the voltage 2 (7) at the capacitor is greater than 6.5 V, the relay is turned on as long as the switch ”WIWA” is closed. The after-wipe-time begins after the switch is open whereas the sources D and F are switched off and the source E is activated. Source E discharges the capacitor till the voltage is less than 2.2 V. The relay is off and the wiper-motor is supplied via the park switch until the park position will be reached. The after-wipe-time is determined by the current source E which can be regulated with the external resistor RTime. Afterwards the source A discharges the capacitor. The relay switch off is independent of the park switch S1. Interval and WIWA Functions The interval function is interrupted immediately when the wipe/ wash mode is activated. The current source A discharges the capacitor to a value of 2 V, afterwards the normal wash function starts. Interval wiping starts immediately when the after-wipetime is over. The switching delays are slightly shorter, because the capacitor is already charged to a value of 2 V. The wipe/ wash function is not interrupted when interval switch S2 is activated. Interval function begins after the WIWA function is over. Rev. A4, 10-Apr-01 U642B 10 k 47 F 10 V C 5 4 3 2 C R 2 1 510 2 22 F 10 V R 4 Rtime = 130 k R S 1 10 k 5 U642B 2.7 k S R 1 1 R 6 6 7 8 Relay R 2 3 10 k WIWA Park switch M M S 3 31 Wiper motor Interval switch 15 Water pump 94 8951 Figure 3. Application circuit with interval and wipe/wash operation Rev. A4, 10-Apr-01 3 (7) U642B Absolute Maximum Ratings Parameters Symbol Value Unit VBatt 28 V I8 I8 I7 I7 1.5 150 200 1.2 A mA mA A I6 I5 I2 Ptot 50 50 50 500 mA mW Storage temperature range Tstg –55 to +125 °C Ambient temperature range Tamb –40 to +85 °C Symbol Value Unit RthJA RthJA 120 160 K/W K/W Supply voltage t = 60 s Terminal 15, Pin 8 Supply current t = 2 ms t = 200 ms Relay control output current (DC) t = 200 ms Pulse current (control inputs) t = 200 ms Power dissipation Park switch, S1 Wipe/Wash switch, S3 Interval switch, S2 Tamb = 90°C Pin 8 Pin 7 Pin 6 Pin 5 Pin 2 Thermal Resistance Parameters Junction ambient DIP8 SO8 Electrical Characteristics VBatt = 12 V, Tamb = 25°C, reference point is Pin 8 (see figure 3) unless otherwise specified. Parameters Test Conditions / Pins Supply voltage Supply current Pin 8 Symbol Min. VBatt 9 Typ. Max. Unit 16.5 V I8 10 mA V1 7.6 V Threshold current I1 –50 mA Threshold voltage VBatt 35 V Z-diode limitation Overvoltage Relay control output Saturation voltage Pin 7 I7 = 100 mA I7 = 200 mA Leakage current Park switch Internal pull-up resistance Input Ct R6 = 10 k I6 = –10 mA I6 = 10 mA Pin 3 Internal resistance Interval input, R2 = 2.7 to 30 k Protection diode 4 (7) –1.0 –1.5 V I7 100 A R6 50 k V6 –3.3 V V6 V6 –0.8 7.6 V V R3 100 V2 –0.8 7.6 V Pin 6 Switching threshold voltage Protection diode V7 Pin 2 I2 = –10 mA I2 = 30 mA/10 ms Rev. A4, 10-Apr-01 U642B Electrical Characteristics (continued) VBatt = 12 V, Tamb = 25°C, reference point is Pin 8 (see figure 3) unless otherwise specified. Parameters Test Conditions / Pins WASH Input, R5 = 10 k Symbol Typ. Max. Unit Pin 5 Switching threshold/Hysteresis Protection diode Min. I5 = –10 mA I5 = 10 mA V5 –1.4/–5.4 V V –0.8 7.6 V Switching Characteristics, R4 = 47 k to 300 k, I4 = –150 A Interval time R3 = 0 k R3 = 10 k t2 Prewash delay 4 12 tdel After-wipe-time R4 = 130 k 12 Pin 5 4.4 13.2 s 100 t5 4.75 ms 5.25 5.75 s 16 Rint = 0 14 Interval pause (s ) 10 Interval pause ( s ) 3.6 10.8 Rint = 5 k 8 6 Rint = 10 k 4 12 10 8 6 4 2 0 –40 2 0 –20 0 14005 20 40 60 Temperature ( °C ) 80 100 0 Figure 4. Interval pause = f ( T); Ct = 22 F 6 8 10 12 14 16 18 20 Interval resistor ( k ) 12 Rtime = 51 k 8 VBatt = 8 V 6 Rtime = 51 k 10 Afterwiping time ( s ) 10 Afterwiping time ( s ) 4 Figure 6. Interval pause = f ( RINT); Ct = 22 F 12 Rtime = 130 k 4 Rtime = 300 k 2 0 –40 2 14009 8 VBatt = 16 V 6 Rtime = 130 k 4 Rtime = 300 k 2 –20 14006 0 20 40 60 Temperature ( °C ) 80 Figure 5. Afterwiping time = f ( T); Ct = 22 F Rev. A4, 10-Apr-01 0 –40 100 14007 –20 0 20 40 60 Temperature ( °C ) 80 100 Figure 7. Afterwiping time = f ( T); Ct = 22 F 5 (7) U642B Package Information Package DIP8 Dimensions in mm 9.8 9.5 1.64 1.44 7.77 7.47 4.8 max 6.4 max 0.5 min 0.58 0.48 3.3 0.36 max 9.8 8.2 2.54 7.62 8 5 technical drawings according to DIN specifications 13021 1 4 Package SO8 Dimensions in mm 5.2 4.8 5.00 4.85 3.7 1.4 0.25 0.10 0.4 1.27 6.15 5.85 3.81 8 0.2 3.8 5 technical drawings according to DIN specifications 13034 1 6 (7) 4 Rev. A4, 10-Apr-01 U642B Ozone Depleting Substances Policy Statement It is the policy of Atmel Germany GmbH to 1. Meet all present and future national and international statutory requirements. 2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems with respect to their impact on the health and safety of our employees and the public, as well as their impact on the environment. It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as ozone depleting substances (ODSs). The Montreal Protocol (1987) and its London Amendments (1990) intend to severely restrict the use of ODSs and forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban on these substances. Atmel Germany GmbH has been able to use its policy of continuous improvements to eliminate the use of ODSs listed in the following documents. 1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively 2. Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental Protection Agency (EPA) in the USA 3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C (transitional substances) respectively. Atmel Germany GmbH can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain such substances. We reserve the right to make changes to improve technical design and may do so without further notice. Parameters can vary in different applications. All operating parameters must be validated for each customer application by the customer. Should the buyer use Atmel Wireless & Microcontrollers products for any unintended or unauthorized application, the buyer shall indemnify Atmel Wireless & Microcontrollers against all claims, costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use. Data sheets can also be retrieved from the Internet: http://www.atmel–wm.com Atmel Germany GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany Telephone: 49 (0)7131 67 2594, Fax number: 49 (0)7131 67 2423 Rev. A4, 10-Apr-01 7 (7)