U642B
Ordering Information
Extended Type Number
U642B
Package
DIP8
Remarks
U642B–FP
SO8
Pin Description
Pin
1
Symbol
GND
INT
Function
GND
INT
1
2
8
7
V
S
Ground
2
Interval switch
OUT
3
C
R
Timing capacitor C
t
t
2
U642B
4
Afterwiping time resistance
C
6
5
PARK
3
4
t
5
WASH Wipe/Wash switch
6
PARK
OUT
Park switch for wiper motor
WASH
R
t
7
Relay control output
Supply voltage KI. 15
93 7691
8
V
S
Figure 2. Pinning
Circuit Description
at the capacitor is greater than 6.5 V, the relay is turned
on as long as the switch ”WIWA” is closed.
Interval Function, Pin 2
By closing the interval switch, S , to supply voltage,
2
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
V , the relay is activated. The internal current source
Batt
(Pin 3) which holds the capacitor C in charged state is
switched-off. As soon as there is a positive potential at the
2
park switch (S ), the current source F (see figure 1)
1
charges the capacitor C very fast. After the wiper
2
operation is finished, S is again at ground potential, the
1
relay is in ”off” position – interval pause begins – the
regulated with the external resistor R
. Afterwards the
Time
capacitor C is discharged through the current source C,
2
source A discharges the capacitor. The relay switch off is
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
independent of the park switch S .
1
help of potentiometer R . Now the relay switches on and
3
the next interval cycle begins. Opening of switch S
2
Interval and WIWA Functions
causes the current source A to discharge C immediately
2
The interval function is interrupted immediately when the
wipe/ wash mode is activated. The current source A dis-
charges the capacitor to a value of 2 V, afterwards the
normal wash function starts.
and current sources C and F are switched-off.
Wipe/Wash (WIWA) Operation, Pin 5
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.
By closing the WIWA-switch, S , to supply voltage,
3
V , the water pump starts spraying water on the wind-
Batt
screen, the current source A is switched-off which keeps
the capacitor C in discharged state. Now the capacitor is The wipe/ wash function is not interrupted when interval
2
charged through the current sources D and F, and when af- switch S is activated. Interval function begins after the
2
ter a time interval of approximately 100 ms, the voltage WIWA function is over.
2 (7)
Rev. A4, 10-Apr-01
ATMEL [ ATMEL ]
