Page 1
U642B
Rev. A4, 10-Apr-01 1 (7)
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
Afterwiping 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
Block Diagram
Wipe / wash
comparator
Interval
comparator
Load-dump
comparator
V
Ref
V
Ref
V
Ref
Input
comparator
Park switch
comparator
V
Ref
8
7
6
5
4
1
23
ABC DEF
Logic
V
S
OUT PARK
WASH
R
t
GND INT
C
t
94 8950
Figure 1. Block diagram
Page 2
U642B
Rev. A4, 10-Apr-012 (7)
Ordering Information
Extended Type Number Package Remarks
U642B DIP8
U642B–FP SO8
Pin Description
Pin Symbol Function
1 GND Ground
2 INT Interval switch
3 C
t
Timing capacitor C
2
4 R
t
Afterwiping time resistance
5 WASH Wipe/Wash switch
6 PARK Park switch for wiper motor
7 OUT Relay control output
8 V
S
Supply voltage KI. 15
V
S
OUT
WASH
GND
INT
R
t
C
t
1
2
3
4
8
7
6
5
U642B
93 7691
PARK
Figure 2. Pinning
Circuit Description
Interval Function, Pin 2
By closing the interval switch, S2, to supply voltage,
V
Batt
, 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 S
2
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,
V
Batt
, 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
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 R
Time
. 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 S
2
is activated. Interval function begins after the
WIWA function is over.
Page 3
U642B
Rev. A4, 10-Apr-01 3 (7)
1
2
6
5
8
7
3
4
10 k
10 k
R6R
5
C
1
47 F
10 V
R
2
C
2
22 F
10 V
R
4
R
time
= 130 k
R
1
510
10 k
R
3
S
2
S
3
MM
Relay
Park
switch
31
15
Wiper motor
Interval switch
Water pump
94 8951
S
1
WIWA
U642B
2.7 k
Figure 3. Application circuit with interval and wipe/wash operation
Page 4
U642B
Rev. A4, 10-Apr-014 (7)
Absolute Maximum Ratings
Parameters Symbol Value Unit
Supply voltage t = 60 s Terminal 15, Pin 8 V
Batt
28 V
Supply current t = 2 ms Pin 8
t = 200 ms
I
8
I
8
1.5
150
A
mA
Relay control output current (DC) Pin 7
t = 200 ms
I
7
I
7
200
1.2
mA
A
Pulse current (control inputs) t = 200 ms
Park switch, S
1
Pin 6
Wipe/Wash switch, S
3
Pin 5
Interval switch, S
2
Pin 2
I
6
I
5
I
2
50
50
50
mA
Power dissipation T
amb
= 90°C P
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
SO8
R
thJA
R
thJA
120
160
K/W
K/W
Electrical Characteristics
V
Batt
= 12 V, T
amb
= 25°C, reference point is Pin 8 (see figure 3) unless otherwise specified.
Parameters Test Conditions / Pins Symbol Min. Typ. Max. Unit
Supply voltage Pin 8 V
Batt
9 16.5 V
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 Pin 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 Pin 6
Internal pull-up resistance R6 = 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
Pin 3
Internal resistance R
3
100
Interval input, R2 = 2.7 to 30 k Pin 2
Protection diode I
2
= –10 mA
I
2
= 30 mA/10 ms
V
2
–0.8
7.6
V
Page 5
U642B
Rev. A4, 10-Apr-01 5 (7)
Electrical Characteristics (continued)
V
Batt
= 12 V, T
amb
= 25°C, reference point is Pin 8 (see figure 3) unless otherwise specified.
Parameters Test Conditions / Pins Symbol Min. Typ. Max. Unit
WASH Input, R5 = 10 k Pin 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, R4 = 47 k to 300 k, I4 = –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 Pin 5 t
5
4.75 5.25 5.75 s
0
2
4
6
8
10
12
–40 –20 0 20 40 60 80 100
Interval pause ( s )
Temperature ( °C )14005
R
int
= 0
R
int
= 5 k
R
int
= 10 k
Figure 4. Interval pause = f ( T); Ct = 22 F
0
2
4
6
8
10
12
–40 –20 0 20 40 60 80 100
Afterwiping time ( s )
Temperature ( °C )14006
R
time
= 51 k
R
time
= 130 k
R
time
= 300 k
V
Batt
= 8 V
Figure 5. Afterwiping time = f ( T); Ct = 22 F
0
2
4
6
8
10
12
14
16
0 2 4 6 8 10 12 14 16 18 20
Interval pause (s )
Interval resistor ( k )14009
Figure 6. Interval pause = f ( R
INT
); Ct = 22 F
0
2
4
6
8
10
12
–40 –20 0 20 40 60 80 100
Afterwiping time ( s )
Temperature ( °C )14007
R
time
= 51 k
R
time
= 130 k
R
time
= 300 k
V
Batt
= 16 V
Figure 7. Afterwiping time = f ( T); Ct = 22 F
Page 6
U642B
Rev. A4, 10-Apr-016 (7)
Package Information
13021
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
13034
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
Page 7
U642B
Rev. A4, 10-Apr-01 7 (7)
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
Loading...