U2043B.pdf 데이터시트 (총 10 페이지) - 파일 다운로드 U2043B 데이타시트 다운로드

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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
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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
VBatt or GND.
Figure 1-1. Block Diagram
C1
4
6
Measuring comparator
K 1 V 6-81 mV
2
7
R3 30 m
Shunt
+VS
+ 49
Pilot lamp 5 W
Pulse
R1 generator
3.8 k
K 3 V 6-5 V
5
49 a-Comparator
23 V
IC Ground
3
Relay
8 R2
3.3 k
1 R1
100
GND
- 31
49 a
5 W 21 W 21 W
21 W 21 W 5 W
Indicator lamps
Pilot lamps
Flasher, 30 m
Shunt, Pilot
Lamp to GND or
VBatt
U2043B
Rev. 4720B–AUTO–09/05

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2. Pin Configuration
Figure 2-1. Pinning DIP8/SO8
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GND 1
8 SI
VS 2
REL 3
U2043B
7 LD
6 VS
OSC 4
5 OSC
Table 2-1.
Pin
1
2
3
4
5
6
7
8
Pin Description
Symbol
GND
VS
REL
OSC
OSC
VS
LD
SI
Function
IC ground
Supply voltage VS
Relay driver
C1 Oscillator
R1 Oscillator
Supply voltage VS
Lamp failure detection
Start input (49a)
2 U2043B
4720B–AUTO–09/05

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U2043B
3. Functional Description
3.1 GND (Pin 1)
The integrated circuit is protected against damage via resistor R4 to ground (–31) in the case of
battery reversal. An integrated protection circuit together with external resistances R2 and R4
limits the current pulses in the IC.
3.2 Supply Voltage, VS Power (Pin 2)
The arrangement of the supply connections to pin 2 must be so as to ensure that, on the con-
nection printed circuit board (PCB), the resistance of VS to pin 6 is lower than that to pin 2.
www.Da3ta.S3heet4UR.ceolmay Control Output (Driver, Pin 3)
The relay control output is a high-side driver with a low saturation voltage and capable of driving
a typical automotive relay with a minimum coil resistance of 60.
3.4 Oscillator (Pin 4 and 5)
Flashing frequency, f1, is determined by the R1C1 components as follows (see Figure 1-1 on
page 1):
f1
=
------------------1------------------
R1 × C1 × 1.5
Hz
where
C1 47 µF
R1 = 6.8 kto 510 k
In the case of a lamp outage (see pin 7) the oscillator frequency is switched to the lamp outage
frequency f2 with f2 2.2 × f1.
Duty cycle in normal flashing mode:
Duty cycle in lamp outage mode:
50%
40% (bright phase)
3.5 Supply Voltage, Sense (Pin 6)
For accurate monitoring via the shunt resistor, a minimized layer resistance from point VS/shunt
to pin 6 is recommended.
4720B–AUTO–09/05
3