rev. 4774a?auto?11/03 features interval pause: 4 to 20 s after-wiping time: 2 to 20 s wiper motor's park switch wipe/wash mode priority one external capacitor determines all time sequences relay driver with z-diode interference protection according to vde 0839 or iso/tr 7637/1 load-dump protected description the U642B is a bi-polar integrated circui t designed for the wiper application in the automotive market. it includes wipe, wash and internal mode. functional description as a convenience feature of the windshield wiper, intermittent and wipe/wash opera- tion fuctions are implemented in most of the automobiles. the U642B is a cost-effective solution for an accurate timing function control. wipe/wash mode has priority over interval mode. interval pause and after-wiping time can be set to fixed val- ues 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. figure 1. block diagram wipe/wash comparator interval comparator load-dump comparator input comparator park switch comparator 87 6 5 4 123 abc def logic v s out park wash r t gnd int v ref v ref v ref v ref c t interval- and wipe/wash wiper control ic U642B
2 U642B 4774a?auto?11/03 pin configuration figure 2. pinning vs out wash gnd int rt ct 1 2 3 4 8 7 6 5 U642B park pin description pin symbol function 1 gnd ground 2 int interval switch 3 ct timing capacitor c 2 4 rt after-wiping time resistance 5 wash wipe/wash switch 6 park park switch for wiper motor 7 out relay control output 8 vs supply voltage terminal 15
3 U642B 4774a?auto?11/03 circuit description interval function, pin 2 by closing the interval switch, s 2 , to supply voltage, v batt , the relay is activated. the internal current source (pin 3) which holds the capacitor c 2 in a charged state is switched-off. as soon as there is a positive potential at the park switch (s 1 ), the current source f (see figure 1 on page 1) charges the capacitor c 2 very quickly. after the wiper operation is finished, s 1 is again at ground potential, the relay is in the off position - inter- val pause begins - the capacitor c 2 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 r 3 . now the relay switches on and the next interval cycle begins. opening of switch s 2 causes the current source a to discharge c 2 immediately and current sources c and f are switched-off. wipe/wash (wiwa) operation, pin 5 by closing the wiwa switch, s 3 , to supply voltage, v batt , the water pump starts spraying water on the windshield. during this function, the current source a is switched-off which keeps the capacitor c 2 in a discharged state. now the capacitor is charged through the current sources d and f. if (after a time interval of approximately 100 ms) the voltage at the capacitor is greater than 6.5 v, the relay is turned on as long as the switch wiwa is closed. the after-wiping time begins when the switch is open, the sources d and f are switched off and the source e is activated. source e discharges the capacitor until 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 is reached. the after-wiping time is determined by the current source e which can be regulated with the external resistor r time . when the after-wiping time has elapsed, the source a discharges the capacitor. the relay switch is independent of the park switch s 1 . 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-wipe time 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 the interval switch s 2 is activated. the interval function begins after the wiwa function has elapsed.
4 U642B 4774a?auto?11/03 figure 3. application circuit with interval and wipe/wash operation 1 2 6 5 8 7 3 4 10 k ? r 6 47 f 10 v 22 f r time = 130 k ? 510 ? 10 k ? m m relay park switch 31 15 wiper motor interval switch water pump wiwa U642B 2.7 k ? 10 k ? r 5 c 1 r 1 s 1 r 2 c 2 r 4 s 2 r 3 s 3
5 U642B 4774a?auto?11/03 absolute maximum ratings stresses beyond those listed under ?absolute maximum ratings? may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability . parameters pin symbol value unit supply voltage t = 60 s, terminal 15 8 v batt 28 v supply current t = 2 ms t = 200 ms 8i 8 i 8 1.5 150 a ma relay control output current (dc) t = 200 ms 7 i 7 i 7 200 1.2 ma a pulse current (control inputs) t = 200 ms park switch, s 1 wipe/wash switch, s 3 interval switch, s 2 6 5 2 i 6 i 5 i 2 50 50 50 ma power dissipation t amb = 90 cp tot 500 mw storage temperature range t stg -55 to +125 c ambient temperature range t amb -40 to +85 c thermal resistance parameters symbol value unit junction ambient dip8 r thja 120 k/w so8 r thja 160 k/w
6 U642B 4774a?auto?11/03 electrical characteristics v batt = 12 v, t amb = 25c, reference point is pin 8 (see figure 3 on page 4) unless otherwise specified. parameters test conditions pin symbol min. typ. max. unit supply voltage 8 v batt 916.5v supply current i 8 10 ma z-diode limitation v 1 7.6 v overvoltage threshold current i1 -50 ma threshold voltage v batt 35 v relay control output 7 saturation voltage i 7 = 100 ma i 7 = 200 ma v 7 -1.0 -1.5 v leakage current i 7 100 a park switch 6 internal pull-up resistance r 6 = 10 k r 6 50 k switching threshold voltage v 6 -3.3 v protection diode i 6 = -10 ma i 6 = 10 ma v 6 v 6 -0.8 7.6 v v input c t 3 internal resistance r 3 100 interval input r 2 = 2.7 to 30 k 2 protection diode i 2 = -10 ma i 2 = 30 ma/10 ms v 2 -0.8 7.6 v wash input r 5 = 10 k 5 switching threshold/ hysteresis v 5 -1.4/ -5.4 v protection diode i 5 = -10 ma i 5 = 10 ma v -0.8 7.6 v switching characteristics r 4 = 47 k to 300 k , i 4 = -150 a interval time r 3 = 0 k r 3 = 10 k t 2 3.6 10.8 4 12 4.4 13.2 s prewash delay t del 100 ms after-wipe-time r 4 = 130 k 5t 5 4.75 5.25 5.75 s
7 U642B 4774a?auto?11/03 diagrams figure 4. interval pause = f (t); c t = 22 f figure 5. after-wiping time = f (t); c t = 22 f; v batt = 8 v figure 6. interval pause = f (r int ); c t = 22 f 0 2 4 6 8 10 12 -40 -20 0 20 40 60 80 100 temperature (c) interval pause (s) r int = 10 k ? r int = 5 k ? r int = 0 0 2 4 6 8 10 12 -40 -20 0 20 40 60 80 100 temperature (c) afterwiping time (s) r time = 130 k ? r time = 300 k ? r time = 51 k ? v batt = 8 v 0 2 4 6 8 10 12 14 16 0 2 4 6 8 1012 14 16 1820 interval resistor (k ? ) interval pause (s)
8 U642B 4774a?auto?11/03 figure 7. after-wiping time = f (t); c t = 22 f; v batt = 16 v 0 2 4 6 8 10 12 -40 -20 0 20 40 60 80 100 temperature (c) afterwiping time (s) r time = 130 k ? r time = 300 k ? r time = 51 k ? v batt = 16 v
9 U642B 4774a?auto?11/03 package information ordering information extended type number package remarks U642B dip8 ? U642B-fp so8 ? 9.8 9.5 package dip8 dimensions in mm 1.64 1.44 4.8 max 0.5 min 3.3 0.58 0.48 7.62 2.54 6.4 max 0.36 max 9.8 8.2 7.77 7.47 85 14 technical drawings according to din specifications technical drawings according to din specifications package so8 dimensions in mm 5.00 4.85 0.4 1.27 3.81 1.4 0.25 0.10 5.2 4.8 3.7 3.8 6.15 5.85 0.2 85 14
printed on recycled paper. disclaimer: atmel corporation makes no warranty for the use of its products, other than those expressly contained in the company?s standar d warranty which is detailed in atmel?s terms and conditions located on the company?s web site. the company assumes no responsibi lity for any errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time wi thout notice, and does not make any commitment to update the information contained her ein. no licenses to patents or other intellectual property of atmel are granted by the company in connection with the sale of atmel produc ts, expressly or by implication. atmel?s products are not aut horized for use as critical components in life support devices or systems. atmel corporation atmel operations 2325 orchard parkway san jose, ca 95131, usa tel: 1(408) 441-0311 fax: 1(408) 487-2600 regional headquarters europe atmel sarl route des arsenaux 41 case postale 80 ch-1705 fribourg switzerland tel: (41) 26-426-5555 fax: (41) 26-426-5500 asia room 1219 chinachem golden plaza 77 mody road tsimshatsui east kowloon hong kong tel: (852) 2721-9778 fax: (852) 2722-1369 japan 9f, tonetsu shinkawa bldg. 1-24-8 shinkawa chuo-ku, tokyo 104-0033 japan tel: (81) 3-3523-3551 fax: (81) 3-3523-7581 memory 2325 orchard parkway san jose, ca 95131, usa tel: 1(408) 441-0311 fax: 1(408) 436-4314 microcontrollers 2325 orchard parkway san jose, ca 95131, usa tel: 1(408) 441-0311 fax: 1(408) 436-4314 la chantrerie bp 70602 44306 nantes cedex 3, france tel: (33) 2-40-18-18-18 fax: (33) 2-40-18-19-60 asic/assp/smart cards zone industrielle 13106 rousset cedex, france tel: (33) 4-42-53-60-00 fax: (33) 4-42-53-60-01 1150 east cheyenne mtn. blvd. colorado springs, co 80906, usa tel: 1(719) 576-3300 fax: 1(719) 540-1759 scottish enterprise technology park maxwell building east kilbride g75 0qr, scotland tel: (44) 1355-803-000 fax: (44) 1355-242-743 rf/automotive theresienstrasse 2 postfach 3535 74025 heilbronn, germany tel: (49) 71-31-67-0 fax: (49) 71-31-67-2340 1150 east cheyenne mtn. blvd. colorado springs, co 80906, usa tel: 1(719) 576-3300 fax: 1(719) 540-1759 biometrics/imaging/hi-rel mpu/ high speed converters/rf datacom avenue de rochepleine bp 123 38521 saint-egreve cedex, france tel: (33) 4-76-58-30-00 fax: (33) 4-76-58-34-80 literature requests www.atmel.com/literature 4774a?auto?11/03 ? atmel corporation 2003 . all rights reserved. atmel ? and combinations thereof are the registered tradem arks of atmel corporation or its subsidiaries. other terms and product names may be the trademarks of others.
|
