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U641B Datasheet, PDF (1/10 Pages) ATMEL Corporation – INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Features
• Interval Pause: 4 to 20 s
• After-wiping Time: 2 to 20 s
• Wiper Motor's Park Switch
• 0.6 s Prewash Delay
• 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 U641B is a bi-polar integrated circuit 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 functions are implemented in most of the automobiles. The U641B 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 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 the U641B.
Figure 1. Block Diagram
VS
8
OUT
7
PARK
6
VRef
WASH
5
VRef
Load-dump
comparator
Park switch Input
comparator comparator
Interval and
Wipe/Wash
Wiper Control
IC with Delay
U641B
VRef
VRef
Logic
Wipe/wash
comparator
Interval
comparator
A
B
C
DE
F
1
GND
2
3
4
INT
Ct
Rt
Rev. 4773A–AUTO–11/03