U842B
Wiper Control for Intermittent and Wipe/ Wash Mode
Description
The U842B circuit is designed as an interval and The integrated relay driver is protected against short
wipe/ wash timer for automotive wiper control. The circuits and is switched to conductive condition in the
interval pause can be set in a range from 3 s to 11 s by an case of a load-dump. With only a few external
external 1-k
potentiometer. Wipe/wash mode has components, protection against RF interference and
priority over the interval mode. The U842B controls the transients (ISO/TR 7637-1/3) can be achieved.
wiper motor with/without park switch signal.
Features
Interval input: low side
Fixed pre-wash delay of 400 ms
Dry wiping
Wipe/ wash input: low side
– With park switch signal: 3 cycles
– Without park switch signal: 2.8 s
Inputs INT, WASH and PARK digitally debounced
All inputs with integrated RF protection
Park input: high side (park position)
Output driver protected against short circuit
All time periods determined by RC oscillator
Fixed relay activation time of 500 ms
Adjustable interval pause from 3 s to 11 s
Load-dump protection and interference protection ac-
cording to ISO 7637-1/3 (DIN 40839)
Application
Digital/ wipe-wash control for rear or front wiper
Ordring Information
Extended Type Number
Package
Remarks
U842B
U842B–FP
DIP8
SO8
Pin Description
Pin
1
Symbol
INT
Function
Interval input
1
2
3
4
8
7
6
5
OUT
GND
INT
2
WASH Wipe/ wash input
3
PARK
PAUS
OSC
Park switch input
Pause time adjust
Oscillator input
Supply voltage
Ground
WASH
PARK
PAUS
4
U842B
5
Vs
6
V
S
7
GND
OUT
OSC
8
Relay output
13300
Figure 1. Pinning
TELEFUNKEN Semiconductors
1 (12)
Rev. A2, 03-Feb-97
TEMIC [ TEMIC SEMICONDUCTORS ]
