U642B
Automotive Wipe/Wash or Interval Switch
Description
As a convenience feature of the windshield wiper inter-
mittent and wipe/wash operation are implemented in
most of the automobiles. The U642B controls all timing
functions accurately at a reasonable price level. Interval
pause and afterwiping time can be set to fixed values with
the help of resistors in a broad time range. Added value
can be provided with an individual, continuous adjust-
ment 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
Ordering Information
Extended Type Number
U642B
U642B–FP
Package
DIP8
SO8
Remarks
Block Diagram
VS
8
Relay control
7
S1
6
VRef
Park switch
comparator
WI WA
5
VRef
Input
comparator
Load-dump
comparator
VRef
Logic
VRef
Interval
comparator
Wipe / wash
comparator
A
B
C
D
E
F
1
GND
2
Interval switch
3
Timing (C2)
4
Timing (R)
94 8950
Figure 1. Block diagram
TELEFUNKEN Semiconductors
Rev. A1, 13-Feb-97
1 (6)
TEMIC [ TEMIC SEMICONDUCTORS ]
