U2044B
| Model | U2044B |
| Description | Dual Output Flasher |
| PDF file | Total 6 pages (File size: 180K) |
| Chip Manufacturer | TEMIC |
U2044B
Block Diagram
9
5
+
–
K1
Contact
1
14
R
1
82 k
W
1
+
–
V
Ref1
+
–
+
–
–
+
V
S
–6 V
27.5 V
11
13
GND 10
R
2
220
W
Relay
1
2
3
2
4
R
3
4.7 k
W
R
6
4.7 k
W
R
10
1.2 k
W
–
+
12
V
Ref2
V
S
/2
6
R
9
47 k
W
7
R
8
47 k
W
2
V
S
–81 mV
R
Shunt
30 m
W
30
30
C
1
4.7
m
F
8
30
Hazard warning
R
4
4.7 k
W
right
15
R
5
1.2 k
W
R
7
1.2 k
W
left
31
12700
Figure 2. Application circuit
R
2
for protection against continous reversed polarity: 1 Watt
Functional Description
Pin 1 and Pin 14,
Oscillator
Flashing frequency, f
1
, is determined by the R
1
C
1
components as follows (see figure 2):
f
1
Pin 2 and Pin 3,
Start input right and left
Flashing is disabled as long as the input comparator is tied
zu GND (pull-down resistor R
7
or R
5
). The high side
flasher switch ”left” or ”right” changes the comparator
status and enables the output stage at Pin 11 or Pin 13. R
6
and R
4
are protection resistors for the input stage.
With an open flasher switch the current consumption is
only I 10
m
A. The IC kept in stand-by mode until there
is a voltage drop of V 6.9 V at the pull-down resistor.
Direction mode can only be activated when the ignition
switch is in ON-position as shown in figure 2.
Pin 4,
Start input hazard warnig
In contrast to the direction switches, the hazard input is
[
R
1
1
C
1
C
1
R
1
1.5
Hz
where
47
m
F
+
6.8 k
W
to 510 k
W
In the case of a lamp outage the oscillator frequency is
switched to the lamp outage frequency f
2
with
f
2
2.2 f
1
.
t
[
[
Duty cycle in normal flashing mode: 50%
Duty cycle in lamp outage mode (bright phase): 40%
2 (6)
TELEFUNKEN Semiconductors
Rev. A1, 25-Feb-97
