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