Features
Temperature and Voltage Compensated Frequency
Warning Indication of Lamp Failure by Means of Frequency Doubling
Minimum Lamp Load for Flasher Operation
≥
10W
Relay Output with High Current Carrying Capacity and Low Saturation
Voltage
•
Low Susceptibility to EMI
•
•
•
•
1. Description
The integrated circuit U2043B is used in relay-controlled automotive flashers where a
high EMC level is required. A lamp outage is indicated by frequency doubling during
hazard mode as well as direction mode. The pilot lamp can be connected either to
V
Batt
or GND.
Figure 1-1.
Block Diagram
+V
S
+ 49
6
C
1
Measuring comparator
4
K
1
V
6
-81 mV
7
Pilot lamp
Pulse
generator
3.8 k
Ω
8
K
3
V
6
-5 V
49 a-Comparator
23 V
1
IC Ground
R
1
100
Ω
GND
- 31
5 W 21 W 21 W
21 W
Indicator lamps
Pilot lamps
21 W 5 W
3
Relay
R
2
3.3 k
Ω
49 a
5W
2
R
3
Shunt
30 m
Ω
Flasher, 30 mΩ
Shunt, Pilot
Lamp to GND or
V
Batt
U2043B
R
1
5
Rev. 4720B–AUTO–09/05
ATMEL [ ATMEL CORPORATION ]
