U642B-MFP Atmel, U642B-MFP Datasheet - Page 4

• Manufacturer Part Number: U642B-MFP
• Description: IC CONTROL WIPE/WASH 8-SOIC
• Manufacturer: Atmel

Specifications of U642B-MFP

• Applications: Special Purpose
• Number Of Outputs: 1
• Voltage - Supply: 9 V ~ 16.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SO-8
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Output: -
• Voltage - Load: -

4. Circuit Description
4.1
4.2
4.3
4
Interval Function, Pin 2
Wipe/Wash (WIWA) Operation, Pin 5
Interval and WIWA Functions
U642B
By closing the interval switch, S
rent source (pin 3) which holds the capacitor C
there is a positive potential at the park switch (S
2) charges the capacitor C
ground potential, the relay is in the off position - interval pause begins - the capacitor C
charged through the current source C, till the voltage at pin 3 is below the threshold of 2V.
Interval pause can be adjusted between 4s to 20s with the help of potentiometer R
relay switches on and the next interval cycle begins. Opening of switch S
source A to discharge C
By closing the WIWA switch, S
on the windshield. During this function, the current source A is switched-off which keeps the
capacitor C
and F. If (after a time interval of approximately 100 ms) the voltage at the capacitor is greater
than 6.5V, 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 2.2V.
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
charges the capacitor. The relay switch is independent of the park switch S
The interval function is interrupted immediately when the wipe/wash mode is activated. The cur-
rent source A discharges the capacitor to a value of 2V, 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 2V.
The wipe/wash function is not interrupted when the interval switch S
function begins after the WIWA function has elapsed.
2
in a discharged state. Now the capacitor is charged through the current sources D
2
immediately and current sources C and F are switched-off.
2
Time
very quickly. After the wiper operation is finished, S
3
2
, to supply voltage, V
, to supply voltage, V
. When the after-wiping time has elapsed, the source A dis-
2
1
), the current source F (see
in a charged state is switched-off. As soon as
Batt
Batt
, the relay is activated. The internal cur-
, the water pump starts spraying water
2
is activated. The interval
1
2
.
Figure 2-1 on page
causes the current
4774C–AUTO–10/07
1
is again at
3
. Now the
2
is dis-