U2043B-MY Atmel, U2043B-MY Datasheet - Page 4

• Manufacturer Part Number: U2043B-MY
• Description: IC FLASH CONTROL 10W SGL 8DIP
• Manufacturer: Atmel
• Type: Automotive, Flasherr

Specifications of U2043B-MY

• Current - Supply: 7mA
• Current - Output: 100µA
• Voltage - Supply: 9 V ~ 15 V
• Operating Temperature: -40°C ~ 95°C
• Package / Case: 8-DIP
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

3.6
3.7
4
Lamp Outage Detection (Pin 7)
Start Input (Pin 8)
U2043B
The lamp current is monitored via an external shunt resistor R
with its reference voltage of typically 81 mV (V
lamps is detected according to the following calculation:
Nominal current of 1 lamp:
Nominal current of 2 lamps:
We recommend setting the detection threshold in the middle of the current range:
I
Thus, the shunt resistor is calculated as:
R
R
Comparator K1’s reference voltage is matched to the characteristics of filament lamps (see sec-
tion “Control Signal Threshold”).
The combination of the shunt resistor and the resistance of the wire harness prevents pin 7 from
a too high voltage in the case of shorted lamps.
Start condition for flashing:
The voltage at pin 8 has to be less than V
Humidity and dirt may decrease the resistance between 49a and GND. If this leakage resistance
is > 5 k the IC is still kept in its off-condition. In this case the voltage at pin 8 is greater than
V
During the bright phase the voltage at pin 8 is above the K2 threshold, during the dark phase it is
below the K3 threshold. For proper start conditions a minimum lamp wattage of 10W is required.
outage
S
3
3
= V
= 81 mV/2.7 A = 30 m
– 5V.
T
(K1)/I
2.7A
outage
21W/(VS = 12V):
2
21W/(V
S
S
– 5V (flasher switch closed).
= 12V):
S
= 12V). The outage of one lamp out of two
I
I
lamp
lamp
= 1.75A
= 3.5A
3
and an internal comparator K1
4720B–AUTO–09/05